diff --git a/examples/biteme.lol.cpp b/examples/biteme.lol.cpp
index 9038dc0..7f1da40 100644
--- a/examples/biteme.lol.cpp
+++ b/examples/biteme.lol.cpp
@@ -51,8 +51,8 @@ int main() {
     docpp::HTML::HTMLSection div2{docpp::HTML::SECTION_DIV, {docpp::HTML::HTMLProperty("align", "center")}};
     docpp::HTML::HTMLSection form{"form", {{docpp::HTML::HTMLProperty("action", "https://google.com/search"), docpp::HTML::HTMLProperty("method", "get")}}};
 
-    form.push_back({"input", docpp::HTML::HTMLElementProperties({docpp::HTML::HTMLProperty("type", "text"), docpp::HTML::HTMLProperty("name", "q")}), "", docpp::HTML::TYPE_SELF_CLOSING});
-    form.push_back({"input", docpp::HTML::HTMLElementProperties({docpp::HTML::HTMLProperty("type", "submit"), docpp::HTML::HTMLProperty("value", "Search!")}), "", docpp::HTML::TYPE_SELF_CLOSING});
+    form.push_back({"input", docpp::HTML::HTMLProperties({docpp::HTML::HTMLProperty("type", "text"), docpp::HTML::HTMLProperty("name", "q")}), "", docpp::HTML::TYPE_SELF_CLOSING});
+    form.push_back({"input", docpp::HTML::HTMLProperties({docpp::HTML::HTMLProperty("type", "submit"), docpp::HTML::HTMLProperty("value", "Search!")}), "", docpp::HTML::TYPE_SELF_CLOSING});
 
     div2.push_back(form);
     html.push_back(div2);
diff --git a/examples/hello-world.cpp b/examples/hello-world.cpp
index 838438c..951fad0 100644
--- a/examples/hello-world.cpp
+++ b/examples/hello-world.cpp
@@ -22,7 +22,7 @@ int main() {
      * The first argument is the type of section, and this can either be a predefined value (e.g., docpp::HTML::SECTION_HTML) or a
      * custom value in the form of an std::string object.
      *
-     * The second argument is an HTMLElementProperties object, which is a collection of HTMLProperty objects. Each property is a std::pair of an
+     * The second argument is an HTMLProperties object, which is a collection of HTMLProperty objects. Each property is a std::pair of an
      * attribute name and an attribute value. If you don't want to specify any attributes, you can pass an empty HTMLElementAttributes object.
      * If you need to change the tag and/or attributes later, you can use the set() method.
      *
@@ -40,7 +40,7 @@ int main() {
     /* This is an HTML element. Unlike a section, an element cannot hold any other elements or sections, rather it holds text and/or attributes.
      * The first argument is the type of element, and this should simply be the tag name (e.g., "p", "h1", "a", etc.).
      *
-     * The second argument is an HTMLElementProperties object, which is a collection of HTMLProperty objects. Each property is a std::pair of an
+     * The second argument is an HTMLProperties object, which is a collection of HTMLProperty objects. Each property is a std::pair of an
      * attribute name and an attribute value. If you don't want to specify any attributes, you can pass an empty HTMLElementAttributes object.
      * If you need to change the element's tag, attributes, type or text later, you can use the set() method.
      *
diff --git a/include/docpp.hpp b/include/docpp.hpp
index 9654190..5b8a54c 100644
--- a/include/docpp.hpp
+++ b/include/docpp.hpp
@@ -16,11 +16,43 @@
 #include <string>
 #include <vector>
 #include <unordered_map>
+#include <map>
 
 /**
  * @brief A namespace to represent HTML elements and documents
  */
 namespace docpp {
+    /**
+     * @brief A class to represent an exception when an index is out of range
+     */
+    class out_of_range : public std::exception {
+        private:
+            const char* message{"Out of range"};
+        public:
+            const char* what() const noexcept override {
+                return message;
+            }
+            out_of_range() = default;
+            out_of_range(const char* message) : message(message) {};
+    };
+
+    /**
+     * @brief A class to represent an exception when an argument is invalid
+     */
+    class invalid_argument : public std::exception {
+        private:
+            const char* message{"Invalid argument"};
+        public:
+            const char* what() const noexcept override {
+                return message;
+            }
+            invalid_argument() = default;
+            invalid_argument(const char* message) : message(message) {};
+    };
+
+    /**
+     * @brief A namespace to represent HTML elements and documents
+     */
     namespace HTML {
         enum {
             SECTION_EMPTY,
@@ -100,11 +132,57 @@ namespace docpp {
         /**
          * @brief A class to represent the properties of an HTML element
          */
-        class HTMLElementProperties {
+        class HTMLProperties {
             private:
                 std::vector<HTMLProperty> properties{};
             protected:
             public:
+                using iterator = std::vector<HTMLProperty>::iterator;
+                using const_iterator = std::vector<HTMLProperty>::const_iterator;
+                using reverse_iterator = std::vector<HTMLProperty>::reverse_iterator;
+                using const_reverse_iterator = std::vector<HTMLProperty>::const_reverse_iterator;
+
+                /**
+                 * @brief Return an iterator to the beginning.
+                 * @return iterator The iterator to the beginning.
+                 */
+                iterator begin() { return properties.begin(); }
+                /**
+                 * @brief Return an iterator to the end.
+                 * @return iterator The iterator to the end.
+                 */
+                iterator end() { return properties.end(); }
+                /**
+                 * @brief Return a const iterator to the beginning.
+                 * @return const_iterator The const iterator to the beginning.
+                 */
+                const_iterator cbegin() const { return properties.cbegin(); }
+                /**
+                 * @brief Return a const iterator to the end.
+                 * @return const_iterator The const iterator to the end.
+                 */
+                const_iterator cend() const { return properties.cend(); }
+                /**
+                 * @brief Return a reverse iterator to the beginning.
+                 * @return reverse_iterator The reverse iterator to the beginning.
+                 */
+                reverse_iterator rbegin() { return properties.rbegin(); }
+                /**
+                 * @brief Return a reverse iterator to the end.
+                 * @return reverse_iterator The reverse iterator to the end.
+                 */
+                reverse_iterator rend() { return properties.rend(); }
+                /**
+                 * @brief Return a const reverse iterator to the beginning.
+                 * @return const_reverse_iterator The const reverse iterator to the beginning.
+                 */
+                const_reverse_iterator crbegin() { return properties.crbegin(); }
+                /**
+                 * @brief Return a const reverse iterator to the end.
+                 * @return const_reverse_iterator The const reverse iterator to the end.
+                 */
+                const_reverse_iterator crend() { return properties.crend(); }
+
                 /**
                  * @brief The npos value
                  */
@@ -187,25 +265,27 @@ namespace docpp {
                  */
                 void push_back(const HTMLProperty& property);
                 /**
-                 * @brief Construct a new HTMLElementProperties object
+                 * @brief Construct a new HTMLProperties object
                  * @param properties The properties to set
                  */
-                HTMLElementProperties(const std::vector<HTMLProperty>& properties);
+                HTMLProperties(const std::vector<HTMLProperty>& properties);
                 /**
-                 * @brief Construct a new HTMLElementProperties object
+                 * @brief Construct a new HTMLProperties object
                  * @param property The property to add
                  */
-                HTMLElementProperties(const HTMLProperty& property);
+                HTMLProperties(const HTMLProperty& property);
                 /**
-                 * @brief Construct a new HTMLElementProperties object
+                 * @brief Construct a new HTMLProperties object
                  */
-                HTMLElementProperties() = default;
-                HTMLElementProperties operator=(const HTMLElementProperties& properties);
-                HTMLElementProperties operator=(const std::vector<HTMLProperty>& properties);
-                HTMLElementProperties operator=(const HTMLProperty& property);
+                HTMLProperties() = default;
+                HTMLProperties operator=(const HTMLProperties& properties);
+                HTMLProperties operator=(const std::vector<HTMLProperty>& properties);
+                HTMLProperties operator=(const HTMLProperty& property);
                 void operator+=(const HTMLProperty& property);
         };
 
+        using HTMLElementProperties = HTMLProperties;
+
         /**
          * @brief A class to represent an HTML element
          */
@@ -214,7 +294,7 @@ namespace docpp {
                 std::string tag{};
                 std::string data{};
                 int type{TYPE_NON_SELF_CLOSING};
-                HTMLElementProperties properties{};
+                HTMLProperties properties{};
             protected:
             public:
                 /**
@@ -228,7 +308,7 @@ namespace docpp {
                  * @param properties The properties of the element
                  * @param data The data of the element
                  */
-                HTMLElement(const std::string& tag, const HTMLElementProperties& properties = {}, const std::string& data = {}, const int type = TYPE_NON_SELF_CLOSING);
+                HTMLElement(const std::string& tag, const HTMLProperties& properties = {}, const std::string& data = {}, const int type = TYPE_NON_SELF_CLOSING);
                 /**
                  * @brief Construct a new HTMLElement object
                  */
@@ -239,7 +319,7 @@ namespace docpp {
                  * @param id The id of the element
                  * @param classes The classes of the element
                  */
-                void set(const std::string& tag, const HTMLElementProperties& properties = {}, const std::string& data = {}, const int type = TYPE_NON_SELF_CLOSING);
+                void set(const std::string& tag, const HTMLProperties& properties = {}, const std::string& data = {}, const int type = TYPE_NON_SELF_CLOSING);
 
                 /**
                  * @brief Get the element in the form of an HTML tag.
@@ -269,12 +349,41 @@ namespace docpp {
             private:
                 int index{};
                 std::string tag{};
-                HTMLElementProperties properties{};
+                HTMLProperties properties{};
 
-                std::unordered_map<int, HTMLElement> elements{};
+                std::map<int, HTMLElement> elements{};
                 std::unordered_map<int, HTMLSection> sections{};
             protected:
             public:
+                /**
+                 * @brief A class to represent an iterator for the HTMLSection class
+                 */
+                template <typename T>
+                class sect_iterator {
+                    private:
+                        T element{};
+                    public:
+                        sect_iterator(const T& element) : element(element) {}
+                        sect_iterator operator++() { return ++element; }
+                        HTMLElement operator*() { return element->second; }
+                        bool operator==(const sect_iterator& other) { return element == other.element; }
+                        bool operator!=(const sect_iterator& other) { return element != other.element; }
+                };
+
+                using iterator = sect_iterator<std::map<int, HTMLElement>::iterator>;
+                using const_iterator = sect_iterator<std::map<int, HTMLElement>::const_iterator>;
+                using reverse_iterator = sect_iterator<std::map<int, HTMLElement>::reverse_iterator>;
+                using const_reverse_iterator = sect_iterator<std::map<int, HTMLElement>::const_reverse_iterator>;
+
+                iterator begin() { return iterator(elements.begin()); }
+                iterator end() { return iterator(elements.end()); }
+                const_iterator cbegin() const { return const_iterator(elements.cbegin()); }
+                const_iterator cend() const { return const_iterator(elements.cend()); }
+                reverse_iterator rbegin() { return reverse_iterator(elements.rbegin()); }
+                reverse_iterator rend() { return reverse_iterator(elements.rend()); }
+                const_reverse_iterator crbegin() { return const_reverse_iterator(elements.crbegin()); }
+                const_reverse_iterator crend() { return const_reverse_iterator(elements.crend()); }
+
                 /**
                  * @brief The npos value
                  */
@@ -388,13 +497,13 @@ namespace docpp {
                  * @param tag The tag of the section
                  * @param properties The properties of the section
                  */
-                HTMLSection(const std::string& tag, const HTMLElementProperties& properties = {});
+                HTMLSection(const std::string& tag, const HTMLProperties& properties = {});
                 /**
                  * @brief Construct a new HTMLSection object
                  * @param tag The tag of the section
                  * @param properties The properties of the section
                  */
-                HTMLSection(const int tag, const HTMLElementProperties& properties = {});
+                HTMLSection(const int tag, const HTMLProperties& properties = {});
                 /**
                  * @brief Construct a new HTMLSection object
                  */
@@ -405,14 +514,14 @@ namespace docpp {
                  * @param id The id of the section
                  * @param classes The classes of the section
                  */
-                void set(const std::string& tag, const HTMLElementProperties& properties = {});
+                void set(const std::string& tag, const HTMLProperties& properties = {});
                 /**
                  * @brief Set the tag, id, and classes of the section
                  * @param tag The tag of the section
                  * @param id The id of the section
                  * @param classes The classes of the section
                  */
-                void set(const int tag, const HTMLElementProperties& properties = {});
+                void set(const int tag, const HTMLProperties& properties = {});
                 /**
                  * @brief Swap two elements in the section
                  * @param index1 The index of the first element
@@ -512,6 +621,9 @@ namespace docpp {
         };
     } // namespace HTML
 
+    /**
+     * @brief A namespace to represent CSS elements and documents
+     */
     namespace CSS {
         enum {
             FORMATTING_NONE,
@@ -519,6 +631,9 @@ namespace docpp {
             FORMATTING_NEWLINE,
         };
 
+        /**
+         * @brief A class to represent a CSS property
+         */
         class CSSProperty {
             private:
                 std::pair<std::string, std::string> property{};
@@ -588,6 +703,52 @@ namespace docpp {
                 std::pair<std::string, std::vector<CSSProperty>> element{};
             protected:
             public:
+                using iterator = std::vector<CSSProperty>::iterator;
+                using const_iterator = std::vector<CSSProperty>::const_iterator;
+                using reverse_iterator = std::vector<CSSProperty>::reverse_iterator;
+                using const_reverse_iterator = std::vector<CSSProperty>::const_reverse_iterator;
+
+                /**
+                 * @brief Return an iterator to the beginning.
+                 * @return iterator The iterator to the beginning.
+                 */
+                iterator begin() { return element.second.begin(); }
+                /**
+                 * @brief Return an iterator to the end.
+                 * @return iterator The iterator to the end.
+                 */
+                iterator end() { return element.second.end(); }
+                /**
+                 * @brief Return a const iterator to the beginning.
+                 * @return const_iterator The const iterator to the beginning.
+                 */
+                const_iterator cbegin() const { return element.second.cbegin(); }
+                /**
+                 * @brief Return a const iterator to the end.
+                 * @return const_iterator The const iterator to the end.
+                 */
+                const_iterator cend() const { return element.second.cend(); }
+                /**
+                 * @brief Return a reverse iterator to the beginning.
+                 * @return reverse_iterator The reverse iterator to the beginning.
+                 */
+                reverse_iterator rbegin() { return element.second.rbegin(); }
+                /**
+                 * @brief Return a reverse iterator to the end.
+                 * @return reverse_iterator The reverse iterator to the end.
+                 */
+                reverse_iterator rend() { return element.second.rend(); }
+                /**
+                 * @brief Return a const reverse iterator to the beginning.
+                 * @return const_reverse_iterator The const reverse iterator to the beginning.
+                 */
+                const_reverse_iterator crbegin() { return element.second.crbegin(); }
+                /**
+                 * @brief Return a const reverse iterator to the end.
+                 * @return const_reverse_iterator The const reverse iterator to the end.
+                 */
+                const_reverse_iterator crend() { return element.second.crend(); }
+
                 /**
                  * @brief The npos value
                  */
@@ -712,6 +873,52 @@ namespace docpp {
                 std::vector<CSSElement> elements{};
             protected:
             public:
+                using iterator = std::vector<CSSElement>::iterator;
+                using const_iterator = std::vector<CSSElement>::const_iterator;
+                using reverse_iterator = std::vector<CSSElement>::reverse_iterator;
+                using const_reverse_iterator = std::vector<CSSElement>::const_reverse_iterator;
+
+                /**
+                 * @brief Return an iterator to the beginning.
+                 * @return iterator The iterator to the beginning.
+                 */
+                iterator begin() { return elements.begin(); }
+                /**
+                 * @brief Return an iterator to the end.
+                 * @return iterator The iterator to the end.
+                 */
+                iterator end() { return elements.end(); }
+                /**
+                 * @brief Return a const iterator to the beginning.
+                 * @return const_iterator The const iterator to the beginning.
+                 */
+                const_iterator cbegin() const { return elements.cbegin(); }
+                /**
+                 * @brief Return a const iterator to the end.
+                 * @return const_iterator The const iterator to the end.
+                 */
+                const_iterator cend() const { return elements.cend(); }
+                /**
+                 * @brief Return a reverse iterator to the beginning.
+                 * @return reverse_iterator The reverse iterator to the beginning.
+                 */
+                reverse_iterator rbegin() { return elements.rbegin(); }
+                /**
+                 * @brief Return a reverse iterator to the end.
+                 * @return reverse_iterator The reverse iterator to the end.
+                 */
+                reverse_iterator rend() { return elements.rend(); }
+                /**
+                 * @brief Return a const reverse iterator to the beginning.
+                 * @return const_reverse_iterator The const reverse iterator to the beginning.
+                 */
+                const_reverse_iterator crbegin() { return elements.crbegin(); }
+                /**
+                 * @brief Return a const reverse iterator to the end.
+                 * @return const_reverse_iterator The const reverse iterator to the end.
+                 */
+                const_reverse_iterator crend() { return elements.crend(); }
+
                 /**
                  * @brief The npos value
                  */
diff --git a/src/docpp.cpp b/src/docpp.cpp
index d7fbed7..fc1fa12 100644
--- a/src/docpp.cpp
+++ b/src/docpp.cpp
@@ -15,8 +15,6 @@
 #include <include/docpp.hpp>
 #include <string>
 #include <vector>
-#include <unordered_map>
-#include <stdexcept>
 
 docpp::HTML::HTMLProperty::HTMLProperty(const std::string& key, const std::string& value) {
     this->setKey(key);
@@ -51,74 +49,74 @@ void docpp::HTML::HTMLProperty::set(const std::pair<std::string, std::string>& p
     this->property = property;
 }
 
-docpp::HTML::HTMLElementProperties::HTMLElementProperties(const std::vector<docpp::HTML::HTMLProperty>& properties) {
+docpp::HTML::HTMLProperties::HTMLProperties(const std::vector<docpp::HTML::HTMLProperty>& properties) {
     this->set(properties);
 }
 
-docpp::HTML::HTMLElementProperties::HTMLElementProperties(const docpp::HTML::HTMLProperty& property) {
+docpp::HTML::HTMLProperties::HTMLProperties(const docpp::HTML::HTMLProperty& property) {
     this->push_back(property);
 }
 
-docpp::HTML::HTMLElementProperties docpp::HTML::HTMLElementProperties::operator=(const docpp::HTML::HTMLProperty& property) {
+docpp::HTML::HTMLProperties docpp::HTML::HTMLProperties::operator=(const docpp::HTML::HTMLProperty& property) {
     this->properties = {property};
     return *this;
 }
 
-docpp::HTML::HTMLElementProperties docpp::HTML::HTMLElementProperties::operator=(const docpp::HTML::HTMLElementProperties& properties) {
+docpp::HTML::HTMLProperties docpp::HTML::HTMLProperties::operator=(const docpp::HTML::HTMLProperties& properties) {
     this->set(properties.getProperties());
     return *this;
 }
 
-docpp::HTML::HTMLElementProperties docpp::HTML::HTMLElementProperties::operator=(const std::vector<docpp::HTML::HTMLProperty>& properties) {
+docpp::HTML::HTMLProperties docpp::HTML::HTMLProperties::operator=(const std::vector<docpp::HTML::HTMLProperty>& properties) {
     this->set(properties);
     return *this;
 }
 
-void docpp::HTML::HTMLElementProperties::operator+=(const docpp::HTML::HTMLProperty& property) {
+void docpp::HTML::HTMLProperties::operator+=(const docpp::HTML::HTMLProperty& property) {
     this->push_back(property);
 }
 
-std::vector<docpp::HTML::HTMLProperty> docpp::HTML::HTMLElementProperties::getProperties() const {
+std::vector<docpp::HTML::HTMLProperty> docpp::HTML::HTMLProperties::getProperties() const {
     return this->properties;
 }
 
-docpp::HTML::HTMLProperty docpp::HTML::HTMLElementProperties::at(const int index) const {
+docpp::HTML::HTMLProperty docpp::HTML::HTMLProperties::at(const int index) const {
     if (index < 0 || index >= this->properties.size()) {
-        throw std::out_of_range("Index out of range");
+        throw docpp::out_of_range("Index out of range");
     }
 
     return this->properties.at(index);
 }
 
-void docpp::HTML::HTMLElementProperties::set(const std::vector<docpp::HTML::HTMLProperty>& properties) {
+void docpp::HTML::HTMLProperties::set(const std::vector<docpp::HTML::HTMLProperty>& properties) {
     this->properties = properties;
 }
 
-void docpp::HTML::HTMLElementProperties::insert(const int index, const docpp::HTML::HTMLProperty& property) {
+void docpp::HTML::HTMLProperties::insert(const int index, const docpp::HTML::HTMLProperty& property) {
     if (index < 0 || index >= this->properties.size()) {
-        throw std::out_of_range("Index out of range");
+        throw docpp::out_of_range("Index out of range");
     }
 
     this->properties.insert(this->properties.begin() + index, property);
 }
 
-void docpp::HTML::HTMLElementProperties::erase(const int index) {
+void docpp::HTML::HTMLProperties::erase(const int index) {
     if (index < 0 || index >= this->properties.size()) {
-        throw std::out_of_range("Index out of range");
+        throw docpp::out_of_range("Index out of range");
     }
 
     this->properties.erase(this->properties.begin() + index);
 }
 
-void docpp::HTML::HTMLElementProperties::push_front(const docpp::HTML::HTMLProperty& property) {
+void docpp::HTML::HTMLProperties::push_front(const docpp::HTML::HTMLProperty& property) {
     this->properties.insert(this->properties.begin(), property);
 }
 
-void docpp::HTML::HTMLElementProperties::push_back(const docpp::HTML::HTMLProperty& property) {
+void docpp::HTML::HTMLProperties::push_back(const docpp::HTML::HTMLProperty& property) {
     this->properties.push_back(property);
 }
 
-int docpp::HTML::HTMLElementProperties::find(const docpp::HTML::HTMLProperty& property) {
+int docpp::HTML::HTMLProperties::find(const docpp::HTML::HTMLProperty& property) {
     for (int i{0}; i < this->properties.size(); i++) {
         if (!this->properties.at(i).getKey().compare(property.getKey())) {
             return i;
@@ -133,10 +131,10 @@ int docpp::HTML::HTMLElementProperties::find(const docpp::HTML::HTMLProperty& pr
         }
     }
 
-    return docpp::HTML::HTMLElementProperties::npos;
+    return docpp::HTML::HTMLProperties::npos;
 }
 
-int docpp::HTML::HTMLElementProperties::find(const std::string& str) {
+int docpp::HTML::HTMLProperties::find(const std::string& str) {
     for (int i{0}; i < this->properties.size(); i++) {
         if (!this->properties.at(i).getKey().compare(str) || !this->properties.at(i).getValue().compare(str)) {
             return i;
@@ -145,34 +143,34 @@ int docpp::HTML::HTMLElementProperties::find(const std::string& str) {
         }
     }
 
-    return docpp::HTML::HTMLElementProperties::npos;
+    return docpp::HTML::HTMLProperties::npos;
 }
 
-docpp::HTML::HTMLProperty docpp::HTML::HTMLElementProperties::front() const {
+docpp::HTML::HTMLProperty docpp::HTML::HTMLProperties::front() const {
     return this->properties.front();
 }
 
-docpp::HTML::HTMLProperty docpp::HTML::HTMLElementProperties::back() const {
+docpp::HTML::HTMLProperty docpp::HTML::HTMLProperties::back() const {
     return this->properties.back();
 }
 
-int docpp::HTML::HTMLElementProperties::size() const {
+int docpp::HTML::HTMLProperties::size() const {
     return this->properties.size();
 }
 
-void docpp::HTML::HTMLElementProperties::swap(const int index1, const int index2) {
+void docpp::HTML::HTMLProperties::swap(const int index1, const int index2) {
     if (index1 < 0 || index1 >= this->properties.size() || index2 < 0 || index2 >= this->properties.size()) {
-        throw std::out_of_range("Index out of range");
+        throw docpp::out_of_range("Index out of range");
     }
 
     std::swap(this->properties[index1], this->properties[index2]);
 }
 
-void docpp::HTML::HTMLElementProperties::swap(const docpp::HTML::HTMLProperty& property1, const docpp::HTML::HTMLProperty& property2) {
+void docpp::HTML::HTMLProperties::swap(const docpp::HTML::HTMLProperty& property1, const docpp::HTML::HTMLProperty& property2) {
     this->swap(this->find(property1), this->find(property2));
 }
 
-docpp::HTML::HTMLElement::HTMLElement(const std::string& tag, const HTMLElementProperties& properties, const std::string& data, const int type) {
+docpp::HTML::HTMLElement::HTMLElement(const std::string& tag, const HTMLProperties& properties, const std::string& data, const int type) {
     this->set(tag, properties, data, type);
 }
 
@@ -185,7 +183,7 @@ void docpp::HTML::HTMLElement::operator+=(const std::string& data) {
     this->data += data;
 }
 
-void docpp::HTML::HTMLElement::set(const std::string& tag, const HTMLElementProperties& properties, const std::string& data, const int type) {
+void docpp::HTML::HTMLElement::set(const std::string& tag, const HTMLProperties& properties, const std::string& data, const int type) {
     this->tag = tag;
     this->data = data;
     this->properties = properties;
@@ -245,7 +243,7 @@ std::string docpp::HTML::HTMLElement::getData() const {
     return this->data;
 }
 
-docpp::HTML::HTMLSection::HTMLSection(const std::string& tag, const HTMLElementProperties& properties) {
+docpp::HTML::HTMLSection::HTMLSection(const std::string& tag, const HTMLProperties& properties) {
     this->tag = tag;
     this->properties = properties;
 }
@@ -272,16 +270,16 @@ docpp::HTML::HTMLElement docpp::HTML::HTMLSection::operator[](const int& index)
     return this->at(index);
 }
 
-docpp::HTML::HTMLSection::HTMLSection(const int tag, const HTMLElementProperties& properties) {
+docpp::HTML::HTMLSection::HTMLSection(const int tag, const HTMLProperties& properties) {
     this->set(tag, properties);
 }
 
-void docpp::HTML::HTMLSection::set(const std::string& tag, const HTMLElementProperties& properties) {
+void docpp::HTML::HTMLSection::set(const std::string& tag, const HTMLProperties& properties) {
     this->tag = tag;
     this->properties = properties;
 }
 
-void docpp::HTML::HTMLSection::set(const int tag, const HTMLElementProperties& properties) {
+void docpp::HTML::HTMLSection::set(const int tag, const HTMLProperties& properties) {
     if (tag == docpp::HTML::SECTION_DIV) {
         this->tag = "div";
     } else if (tag == docpp::HTML::SECTION_BODY) {
@@ -335,7 +333,7 @@ void docpp::HTML::HTMLSection::erase(const int index) {
     }
 
     if (!erased) {
-        throw std::out_of_range("Index out of range");
+        throw docpp::out_of_range("Index out of range");
     }
 }
 
@@ -349,7 +347,7 @@ void docpp::HTML::HTMLSection::erase(const HTMLSection& section) {
         }
     }
 
-    throw std::out_of_range("Section not found");
+    throw docpp::out_of_range("Section not found");
 }
 
 void docpp::HTML::HTMLSection::erase(const HTMLElement& element) {
@@ -362,12 +360,12 @@ void docpp::HTML::HTMLSection::erase(const HTMLElement& element) {
         }
     }
 
-    throw std::out_of_range("Element not found");
+    throw docpp::out_of_range("Element not found");
 }
 
 void docpp::HTML::HTMLSection::insert(const int index, const HTMLElement& element) {
     if (this->sections.find(index) != this->sections.end()) {
-        throw std::invalid_argument("Index already occupied by a section");
+        throw docpp::invalid_argument("Index already occupied by a section");
     } else {
         this->elements[index] = element;
     }
@@ -385,7 +383,7 @@ docpp::HTML::HTMLElement docpp::HTML::HTMLSection::at(const int index) const {
         return this->elements.at(index);
     }
 
-    throw std::out_of_range("Index out of range");
+    throw docpp::out_of_range("Index out of range");
 }
 
 docpp::HTML::HTMLSection docpp::HTML::HTMLSection::at_section(const int index) const {
@@ -393,7 +391,7 @@ docpp::HTML::HTMLSection docpp::HTML::HTMLSection::at_section(const int index) c
         return this->sections.at(index);
     }
 
-    throw std::out_of_range("Index out of range");
+    throw docpp::out_of_range("Index out of range");
 }
 
 int docpp::HTML::HTMLSection::find(const HTMLElement& element) {
@@ -445,7 +443,7 @@ docpp::HTML::HTMLElement docpp::HTML::HTMLSection::front() const {
         return this->elements.at(0);
     }
 
-    throw std::out_of_range("Index out of range");
+    throw docpp::out_of_range("Index out of range");
 }
 
 docpp::HTML::HTMLSection docpp::HTML::HTMLSection::front_section() const {
@@ -453,7 +451,7 @@ docpp::HTML::HTMLSection docpp::HTML::HTMLSection::front_section() const {
         return this->sections.at(0);
     }
 
-    throw std::out_of_range("Index out of range");
+    throw docpp::out_of_range("Index out of range");
 }
 
 docpp::HTML::HTMLElement docpp::HTML::HTMLSection::back() const {
@@ -461,7 +459,7 @@ docpp::HTML::HTMLElement docpp::HTML::HTMLSection::back() const {
         return this->elements.at(this->index - 1);
     }
 
-    throw std::out_of_range("Index out of range");
+    throw docpp::out_of_range("Index out of range");
 }
 
 docpp::HTML::HTMLSection docpp::HTML::HTMLSection::back_section() const {
@@ -469,7 +467,7 @@ docpp::HTML::HTMLSection docpp::HTML::HTMLSection::back_section() const {
         return this->sections.at(this->index - 1);
     }
 
-    throw std::out_of_range("Index out of range");
+    throw docpp::out_of_range("Index out of range");
 }
 
 int docpp::HTML::HTMLSection::size() const {
@@ -564,7 +562,7 @@ void docpp::HTML::HTMLSection::swap(const int index1, const int index2) {
     } else if (this->sections.find(index1) != this->sections.end() && this->sections.find(index2) != this->sections.end()) {
         std::swap(this->sections[index1], this->sections[index2]);
     } else {
-        throw std::out_of_range("Index out of range");
+        throw docpp::out_of_range("Index out of range");
     }
 }
 
@@ -698,7 +696,7 @@ void docpp::CSS::CSSElement::push_back(const CSSProperty& property) {
 
 void docpp::CSS::CSSElement::insert(const int index, const CSSProperty& property) {
     if (index < 0 || index >= this->element.second.size()) {
-        throw std::out_of_range("Index out of range");
+        throw docpp::out_of_range("Index out of range");
     }
 
     this->element.second.insert(this->element.second.begin() + index, property);
@@ -706,7 +704,7 @@ void docpp::CSS::CSSElement::insert(const int index, const CSSProperty& property
 
 void docpp::CSS::CSSElement::erase(const int index) {
     if (index < 0 || index >= this->element.second.size()) {
-        throw std::out_of_range("Index out of range");
+        throw docpp::out_of_range("Index out of range");
     }
 
     this->element.second.erase(this->element.second.begin() + index);
@@ -714,7 +712,7 @@ void docpp::CSS::CSSElement::erase(const int index) {
 
 docpp::CSS::CSSProperty docpp::CSS::CSSElement::at(const int index) const {
     if (index < 0 || index >= this->element.second.size()) {
-        throw std::out_of_range("Index out of range");
+        throw docpp::out_of_range("Index out of range");
     }
 
     return this->element.second.at(index);
@@ -754,7 +752,7 @@ int docpp::CSS::CSSElement::size() const {
 
 void docpp::CSS::CSSElement::swap(const int index1, const int index2) {
     if (index1 < 0 || index1 >= this->element.second.size() || index2 < 0 || index2 >= this->element.second.size()) {
-        throw std::out_of_range("Index out of range");
+        throw docpp::out_of_range("Index out of range");
     }
 
     std::swap(this->element.second[index1], this->element.second[index2]);
@@ -827,7 +825,7 @@ void docpp::CSS::CSSStylesheet::push_back(const CSSElement& element) {
 
 void docpp::CSS::CSSStylesheet::insert(const int index, const CSSElement& element) {
     if (index < 0 || index >= this->elements.size()) {
-        throw std::out_of_range("Index out of range");
+        throw docpp::out_of_range("Index out of range");
     }
 
     this->elements.insert(this->elements.begin() + index, element);
@@ -835,7 +833,7 @@ void docpp::CSS::CSSStylesheet::insert(const int index, const CSSElement& elemen
 
 void docpp::CSS::CSSStylesheet::erase(const int index) {
     if (index < 0 || index >= this->elements.size()) {
-        throw std::out_of_range("Index out of range");
+        throw docpp::out_of_range("Index out of range");
     }
 
     this->elements.erase(this->elements.begin() + index);
@@ -856,7 +854,7 @@ docpp::CSS::CSSElement docpp::CSS::CSSStylesheet::operator[](const int& index) c
 
 docpp::CSS::CSSElement docpp::CSS::CSSStylesheet::at(const int index) const {
     if (index < 0 || index >= this->elements.size()) {
-        throw std::out_of_range("Index out of range");
+        throw docpp::out_of_range("Index out of range");
     }
 
     return this->elements.at(index);
@@ -896,7 +894,7 @@ docpp::CSS::CSSElement docpp::CSS::CSSStylesheet::back() const {
 
 void docpp::CSS::CSSStylesheet::swap(const int index1, const int index2) {
     if (index1 < 0 || index1 >= this->elements.size() || index2 < 0 || index2 >= this->elements.size()) {
-        throw std::out_of_range("Index out of range");
+        throw docpp::out_of_range("Index out of range");
     }
 
     std::swap(this->elements[index1], this->elements[index2]);
diff --git a/tests/test.cpp b/tests/test.cpp
index 31e2707..a5fd8e2 100644
--- a/tests/test.cpp
+++ b/tests/test.cpp
@@ -7,7 +7,7 @@
  * @brief Test cases for the docpp namespace.
  */
 SCENARIO("Test HTML", "[HTML]") {
-    auto test1 = []() {
+    const auto test1 = []() {
         docpp::HTML::HTMLDocument doc{};
         docpp::HTML::HTMLSection html(docpp::HTML::SECTION_HTML, {});
 
@@ -20,7 +20,7 @@ SCENARIO("Test HTML", "[HTML]") {
         body.push_back(docpp::HTML::HTMLElement("h1", {}, "Test Header"));
         body.push_back(docpp::HTML::HTMLElement("p", {}, "Test Paragraph"));
 
-        docpp::HTML::HTMLElementProperties prop{};
+        docpp::HTML::HTMLProperties prop{};
         prop.push_back(docpp::HTML::HTMLProperty(std::pair<std::string, std::string>("id", "test_id")));
 
         body.push_back(docpp::HTML::HTMLElement("p", prop, "Test Paragraph With ID"));
@@ -44,7 +44,7 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(doc.get(docpp::HTML::FORMATTING_NEWLINE) == "<!DOCTYPE html>\n<html>\n<head>\n<title>Test Title</title>\n</head>\n<body>\n<h1>Test Header</h1>\n<p>Test Paragraph</p>\n<p id=\"test_id\">Test Paragraph With ID</p>\n<div>\n<p>Test Paragraph In Div</p>\n</div>\n<p id=\"test_id\" class=\"class1 class2 class3\">Test Paragraph With ID And Class</p>\n</body>\n<footer>\n</footer>\n</html>");
     };
 
-    auto test2 = []() {
+    const auto test2 = []() {
         docpp::HTML::HTMLSection section(docpp::HTML::SECTION_HTML, {});
 
         section.push_back(docpp::HTML::HTMLElement("p", {}, "Test 1"));
@@ -57,7 +57,7 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(section.get(docpp::HTML::FORMATTING_NEWLINE) == "<html>\n<p>Test 1</p>\n<p>Test 3</p>\n</html>");
     };
 
-    auto test3 = []() {
+    const auto test3 = []() {
         docpp::HTML::HTMLSection section = docpp::HTML::HTMLSection(docpp::HTML::SECTION_HTML, {});
 
         section.push_back(docpp::HTML::HTMLElement("p", {}, "Test 1"));
@@ -71,7 +71,7 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(section.get(docpp::HTML::FORMATTING_NEWLINE) == "<html>\n<p>Test 1</p>\n<p>Test 2.5</p>\n<p>Test 3</p>\n</html>");
     };
 
-    auto test4 = []() {
+    const auto test4 = []() {
         docpp::HTML::HTMLSection section = docpp::HTML::HTMLSection(docpp::HTML::SECTION_HTML, {});
 
         section.push_back(docpp::HTML::HTMLElement("p", {}, "Test 1"));
@@ -86,7 +86,7 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(section.get(docpp::HTML::FORMATTING_NEWLINE) == "<html>\n<p>Test 1</p>\n<p>Test 3</p>\n</html>");
     };
 
-    auto test5 = []() {
+    const auto test5 = []() {
         docpp::HTML::HTMLSection section = docpp::HTML::HTMLSection(docpp::HTML::SECTION_HTML, {});
         docpp::HTML::HTMLSection subsection(docpp::HTML::SECTION_DIV, {});
 
@@ -106,7 +106,7 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(doc.get(docpp::HTML::FORMATTING_NEWLINE) == "<!DOCTYPE html>\n<html>\n<div>\n<p>Test 1</p>\n<div>\n<p>Test 2</p>\n</div>\n</div>\n</html>");
     };
 
-    auto test6 = []() {
+    const auto test6 = []() {
         docpp::CSS::CSSStylesheet css{};
         docpp::CSS::CSSElement element{"p", {{"color", "red"}, {"font-size", "16px"}, {"font-family", "Arial"}}};
 
@@ -116,7 +116,7 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(css.get(docpp::CSS::FORMATTING_NEWLINE) == "p {\ncolor: red;\nfont-size: 16px;\nfont-family: Arial;\n}\n");
     };
 
-    auto test7 = []() {
+    const auto test7 = []() {
         docpp::CSS::CSSStylesheet css = docpp::CSS::CSSStylesheet{};
         docpp::CSS::CSSElement element = docpp::CSS::CSSElement{"p", {{"color", "red"}, {"font-size", "16px"}, {"font-family", "Arial"}}};
         docpp::CSS::CSSElement element2{"div", {{"color", "blue"}, {"font-size", "12px"}, {"font-family", "Arial"}}};
@@ -127,7 +127,7 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(css.get() == "div {color: blue;font-size: 12px;font-family: Arial;}p {color: red;font-size: 16px;font-family: Arial;}");
     };
 
-    auto test8 = []() {
+    const auto test8 = []() {
         docpp::CSS::CSSStylesheet css = docpp::CSS::CSSStylesheet{};
         docpp::CSS::CSSElement element = docpp::CSS::CSSElement{"p", {{"color", "red"}, {"font-size", "16px"}, {"font-family", "Arial"}}};
         docpp::CSS::CSSElement element2{"div", {{"color", "blue"}, {"font-size", "12px"}, {"font-family", "Arial"}}};
@@ -140,7 +140,7 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(css.get() == "p {color: red;font-size: 16px;font-family: Arial;}");
     };
 
-    auto test9 = []() {
+    const auto test9 = []() {
         docpp::CSS::CSSStylesheet css = docpp::CSS::CSSStylesheet{};
         docpp::CSS::CSSElement element = docpp::CSS::CSSElement{"p", {{"color", "red"}, {"font-size", "16px"}, {"font-family", "Arial"}}};
         docpp::CSS::CSSElement element2{"div", {{"color", "blue"}, {"font-size", "12px"}, {"font-family", "Arial"}}};
@@ -160,7 +160,7 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(element.get() == "p {font-weight: bold;color: red;font-size: 16px;font-family: Arial;}");
     };
 
-    auto test10 = []() {
+    const auto test10 = []() {
         docpp::HTML::HTMLSection section = docpp::HTML::HTMLSection(docpp::HTML::SECTION_HTML, {});
 
         section.push_back(docpp::HTML::HTMLElement("p", {}, "Test 1"));
@@ -172,7 +172,7 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(section.get() == "<html><p>Test 1</p><p>Test 3</p><p>Test 2</p></html>");
     };
 
-    auto test11 = []() {
+    const auto test11 = []() {
         docpp::HTML::HTMLSection section = docpp::HTML::HTMLSection(docpp::HTML::SECTION_HTML, {});
 
         section.push_back(docpp::HTML::HTMLElement("p", {}, "Test 1"));
@@ -184,7 +184,7 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(section.get() == "<html><p>Test 1</p><p>Test 3</p><p>Test 2</p></html>");
     };
 
-    auto test12 = []() {
+    const auto test12 = []() {
         docpp::HTML::HTMLSection section = docpp::HTML::HTMLSection(docpp::HTML::SECTION_HTML, {});
 
         section.push_back(docpp::HTML::HTMLElement("p", {}, "Test 1"));
@@ -196,7 +196,7 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(section.get() == "<html><p>Test 0</p><p>Test 1</p><p>Test 2</p><p>Test 3</p></html>");
     };
 
-    auto test13 = []() {
+    const auto test13 = []() {
         docpp::HTML::HTMLSection section = docpp::HTML::HTMLSection(docpp::HTML::SECTION_HTML, {});
 
         section.push_back(docpp::HTML::HTMLElement("p", {}, "Test 1"));
@@ -218,7 +218,7 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(section.get() == "<html><p>Test 1</p><p>Test 3</p><p>Test 4</p><p>Test 5</p></html>");
     };
 
-    auto test14 = []() {
+    const auto test14 = []() {
         docpp::CSS::CSSElement element{"p", {{"color", "red"}, {"font-size", "16px"}, {"font-family", "Arial"}}};
 
         const int red = element.find("color");
@@ -238,8 +238,8 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(element.get() == "p {color: red;font-size: 16px;font-family: Arial;}");
     };
 
-    auto test15 = []() {
-        docpp::HTML::HTMLElementProperties prop{};
+    const auto test15 = []() {
+        docpp::HTML::HTMLProperties prop{};
 
         prop.push_back(docpp::HTML::HTMLProperty(std::pair<std::string, std::string>("id", "test_id")));
         prop.push_back(docpp::HTML::HTMLProperty(std::pair<std::string, std::string>("class", "class1 class2 class3")));
@@ -248,25 +248,25 @@ SCENARIO("Test HTML", "[HTML]") {
 
         const int pos = prop.find("class");
 
-        REQUIRE(pos != docpp::HTML::HTMLElementProperties::npos);
+        REQUIRE(pos != docpp::HTML::HTMLProperties::npos);
 
         const int pos2 = prop.find("class2");
 
         REQUIRE(prop.at(pos2).getKey() == "class");
         REQUIRE(prop.at(pos2).getValue() == "class1 class2 class3");
 
-        REQUIRE(pos2 != docpp::HTML::HTMLElementProperties::npos);
+        REQUIRE(pos2 != docpp::HTML::HTMLProperties::npos);
 
         const int pos3 = prop.find("class4");
 
-        REQUIRE(pos3 == docpp::HTML::HTMLElementProperties::npos);
+        REQUIRE(pos3 == docpp::HTML::HTMLProperties::npos);
 
         prop.erase(pos);
 
         REQUIRE(docpp::HTML::HTMLElement("p", prop, {}).get() == "<p id=\"test_id\"></p>");
     };
 
-    auto test16 = []() {
+    const auto test16 = []() {
         docpp::HTML::HTMLDocument doc = docpp::HTML::HTMLSection({});
 
         doc.getSection().push_back(docpp::HTML::HTMLElement("p", {}, "Test 1"));
@@ -284,7 +284,7 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(doc.get() == "<!DOCTYPE html><html><p>Test 4</p><p>Test 5</p><p>Test 6</p><p>Test 7</p></html>");
     };
 
-    auto test17 = []() {
+    const auto test17 = []() {
         docpp::HTML::HTMLSection section = docpp::HTML::HTMLSection(docpp::HTML::SECTION_HTML, {});
 
         section.push_back(docpp::HTML::HTMLElement("p", {}, "Test 1"));
@@ -296,7 +296,7 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(doc.get(docpp::HTML::FORMATTING_PRETTY) == "<!DOCTYPE html>\n<html>\n\t<p>Test 1</p>\n\t<p>Test 2</p>\n\t<p>Test 3</p>\n</html>");
     };
 
-    auto test18 = []() {
+    const auto test18 = []() {
         docpp::HTML::HTMLSection section = docpp::HTML::HTMLSection(docpp::HTML::SECTION_EMPTY, {});
 
         section.push_back(docpp::HTML::HTMLElement("p", {}, "Test 1"));
@@ -306,7 +306,7 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(section.get() == "<p>Test 1</p><p>Test 2</p><p>Test 3</p>");
     };
 
-    auto test19 = []() {
+    const auto test19 = []() {
         docpp::HTML::HTMLSection section = docpp::HTML::HTMLSection(docpp::HTML::SECTION_HTML, {});
 
         section.push_back(docpp::HTML::HTMLElement("p", {}, "Test 1"));
@@ -317,6 +317,62 @@ SCENARIO("Test HTML", "[HTML]") {
         REQUIRE(section.back().get() == "<p>Test 3</p>");
     };
 
+    const auto test20 = []() {
+        docpp::HTML::HTMLProperties prop{};
+
+        prop.push_back(docpp::HTML::HTMLProperty(std::pair<std::string, std::string>("id", "test_id")));
+        prop.push_back(docpp::HTML::HTMLProperty(std::pair<std::string, std::string>("class", "class1 class2 class3")));
+        prop.push_back(docpp::HTML::HTMLProperty(std::pair<std::string, std::string>("style", "color: red; font-size: 16px; font-family: Arial;")));
+
+        for (const docpp::HTML::HTMLProperty& p : prop) {
+            REQUIRE(p.getKey() == "id");
+            REQUIRE(p.getValue() == "test_id");
+            break;
+        }
+
+        for (docpp::HTML::HTMLProperties::iterator it = ++prop.begin(); it != prop.end(); ++it) {
+            REQUIRE(it->getKey() == "class");
+            REQUIRE(it->getValue() == "class1 class2 class3");
+            break;
+        }
+    };
+
+    const auto test21 = []() {
+        docpp::HTML::HTMLSection sect{};
+
+        sect.push_back(docpp::HTML::HTMLElement("p", {}, "Test 1"));
+        sect.push_back(docpp::HTML::HTMLElement("p", {}, "Test 2"));
+        sect.push_back(docpp::HTML::HTMLElement("p", {}, "Test 3"));
+
+        for (const docpp::HTML::HTMLElement& elem : sect) {
+            REQUIRE(elem.get() == "<p>Test 1</p>");
+            break;
+        }
+
+        for (docpp::HTML::HTMLSection::iterator it = ++sect.begin(); it != sect.end(); ++it) {
+            docpp::HTML::HTMLElement elem = *it;
+            REQUIRE(elem.get() == "<p>Test 2</p>");
+            break;
+        }
+    };
+
+    const auto test22 = []() {
+        docpp::HTML::HTMLSection sect{};
+
+        sect.push_back(docpp::HTML::HTMLElement("p", {}, "Test 1"));
+        sect.push_back(docpp::HTML::HTMLElement("p", {}, "Test 2"));
+        sect.push_back(docpp::HTML::HTMLElement("p", {}, "Test 3"));
+
+        bool caught{false};
+        try {
+            sect.at(1337);
+        } catch (const docpp::out_of_range& e) {
+            caught = true;
+        }
+
+        REQUIRE(caught);
+    };
+
     std::vector<void (*)()> tests{
         test1,
         test2,
@@ -337,6 +393,9 @@ SCENARIO("Test HTML", "[HTML]") {
         test17,
         test18,
         test19,
+        test20,
+        test21,
+        test22,
     };
 
     for (const auto& test : tests) {