diff --git a/Tests/String.cpp b/Tests/String.cpp
new file mode 100644
index 0000000..69609bd
--- /dev/null
+++ b/Tests/String.cpp
@@ -0,0 +1,110 @@
+#ifdef DEBUG
+
+#include <string.hpp>
+#include <debug.h>
+
+void TestString()
+{
+    String hw("Hello, world!");
+    debug("String length: %d", hw.length());
+    debug("String capacity: %d", hw.capacity());
+    debug("String data: %s", hw.c_str());
+    if (hw == "Hello, world!" && hw != "World, hello!")
+        debug("String comparison works!");
+    else
+    {
+        error("String comparison doesn't work! \"%s\"", hw.c_str());
+        while (1)
+            ;
+    }
+
+    String hi("Hi");
+    char chi[3];
+    chi[0] = hi[0];
+    chi[1] = hi[1];
+    chi[2] = '\0';
+    if (strcmp(chi, "Hi") == 0)
+        debug("String indexing works!");
+    else
+    {
+        error("String indexing doesn't work! \"%s\" \"%s\"", chi, hi.c_str());
+        while (1)
+            ;
+    }
+
+    hi << " there!";
+    if (hi == "Hi there!")
+        debug("String concatenation works!");
+    else
+    {
+        error("String concatenation doesn't work! \"%s\"", hi.c_str());
+        while (1)
+            ;
+    }
+
+    hi << " " << hw;
+    if (hi == "Hi there! Hello, world!")
+        debug("String concatenation works!");
+    else
+    {
+        error("String concatenation doesn't work! \"%s\"", hi.c_str());
+        while (1)
+            ;
+    }
+
+    String eq0("Hello, world!");
+    String eq1("Hello, world!");
+    String eq2("World, hello!");
+
+    if (eq0 == eq1)
+        debug("String equality works!");
+    else
+    {
+        error("String equality doesn't work! \"%s\" \"%s\"", eq0.c_str(), eq1.c_str());
+        while (1)
+            ;
+    }
+
+    if (eq0 != eq2)
+        debug("String inequality works!");
+    else
+    {
+        error("String inequality doesn't work! \"%s\" \"%s\"", eq0.c_str(), eq2.c_str());
+        while (1)
+            ;
+    }
+
+    char chw[14];
+    int i = 0;
+    foreach (auto c in hw)
+    {
+        chw[i] = c;
+        i++;
+    }
+    chw[i] = '\0';
+
+    if (strcmp(chw, "Hello, world!") == 0)
+        debug("String iteration works!");
+    else
+    {
+        error("String iteration doesn't work! \"%s\" \"%s\" %d", chw, hw.c_str(), i);
+        while (1)
+            ;
+    }
+
+    String a("Hello");
+    String b("World");
+    String c;
+    c = a + ", " + b + "!";
+
+    if (c == "Hello, World!")
+        debug("String addition works!");
+    else
+    {
+        error("String addition doesn't work! \"%s\"", c.c_str());
+        while (1)
+            ;
+    }
+}
+
+#endif // DEBUG
diff --git a/Tests/TypeSize.cpp b/Tests/TypeSize.cpp
index c06c9d9..4431f64 100644
--- a/Tests/TypeSize.cpp
+++ b/Tests/TypeSize.cpp
@@ -103,4 +103,4 @@ __constructor void TestTypeSize()
     debug("__UINTMAX_MAX__ = %#llx", __UINTMAX_MAX__);
 }
 
-#endif
+#endif // DEBUG
diff --git a/Tests/t.h b/Tests/t.h
new file mode 100644
index 0000000..96670db
--- /dev/null
+++ b/Tests/t.h
@@ -0,0 +1,10 @@
+#ifndef __FENNIX_KERNEL_non_constructor_tests_H__
+#define __FENNIX_KERNEL_non_constructor_tests_H__
+#ifdef DEBUG
+
+#include <types.h>
+
+void TestString();
+
+#endif // DEBUG
+#endif // !__FENNIX_KERNEL_non_constructor_tests_H__
diff --git a/include/string.hpp b/include/string.hpp
new file mode 100644
index 0000000..b12d251
--- /dev/null
+++ b/include/string.hpp
@@ -0,0 +1,233 @@
+#ifndef __FENNIX_KERNEL_STRING_H__
+#define __FENNIX_KERNEL_STRING_H__
+
+#include <types.h>
+#include <convert.h>
+#include <debug.h>
+
+// show debug messages
+// #define DEBUG_CPP_STRING 1
+
+#ifdef DEBUG_CPP_STRING
+#define strdbg(m, ...) debug(m, ##__VA_ARGS__)
+#else
+#define strdbg(m, ...)
+#endif
+
+// TODO: Somewhere the delete is called twice, causing a double free error.
+
+/**
+ * @brief String class
+ * String class that can be used to store strings.
+ */
+class String
+{
+private:
+    char *m_Data;
+    int m_Length;
+    int m_Capacity;
+
+public:
+    String(const char *Str = "")
+    {
+        this->m_Length = strlen(Str);
+        this->m_Capacity = this->m_Length + 1;
+        this->m_Data = new char[m_Capacity];
+        strcpy(m_Data, Str);
+        strdbg("New string created: \"%s\" (data: %#lx, length: %d, capacity: %d)", this->m_Data, this->m_Data, this->m_Length, this->m_Capacity);
+    }
+
+    ~String()
+    {
+        strdbg("String deleted: \"%s\" (data: %#lx, length: %d, capacity: %d)", this->m_Data, this->m_Data, this->m_Length, this->m_Capacity);
+        delete[] this->m_Data;
+    }
+
+    int length() const
+    {
+        strdbg("String length: %d", this->m_Length);
+        return this->m_Length;
+    }
+
+    int capacity() const
+    {
+        strdbg("String capacity: %d", this->m_Capacity);
+        return this->m_Capacity;
+    }
+
+    const char *c_str() const
+    {
+        strdbg("String data: \"%s\"", this->m_Data);
+        return this->m_Data;
+    }
+
+    void resize(int NewLength)
+    {
+        strdbg("String resize: %d", NewLength);
+        if (NewLength > this->m_Capacity)
+        {
+            int newCapacity = NewLength + 1;
+            char *newData = new char[newCapacity];
+
+            strcpy(newData, this->m_Data);
+
+            strdbg("old: %#lx, new: %#lx", this->m_Data, newData);
+            delete[] this->m_Data;
+            this->m_Data = newData;
+            this->m_Capacity = newCapacity;
+        }
+        this->m_Length = NewLength;
+        this->m_Data[m_Length] = '\0';
+        strdbg("String resized: \"%s\" (data: %#lx, length: %d, capacity: %d)", this->m_Data, this->m_Data, this->m_Length, this->m_Capacity);
+    }
+
+    void concat(const String &Other)
+    {
+        int NewLength = this->m_Length + Other.m_Length;
+        this->resize(NewLength);
+
+        strcat(m_Data, Other.m_Data);
+        strdbg("String concatenated: \"%s\" (data: %#lx, length: %d, capacity: %d)", this->m_Data, this->m_Data, this->m_Length, this->m_Capacity);
+    }
+
+    String operator+(const String &Other) const
+    {
+        String result = *this;
+        result.concat(Other);
+        strdbg("String added: \"%s\" (data: %#lx, length: %d, capacity: %d)", result.m_Data, result.m_Data, result.m_Length, result.m_Capacity);
+        return result;
+    }
+
+    String operator+(const char *Other) const
+    {
+        String result = *this;
+        result.concat(Other);
+        strdbg("String added: \"%s\" (data: %#lx, length: %d, capacity: %d)", result.m_Data, result.m_Data, result.m_Length, result.m_Capacity);
+        return result;
+    }
+
+    /* warning: implicitly-declared ‘constexpr String::String(const String&)’ is deprecated [-Wdeprecated-copy] */
+    String &operator=(const String &Other) = default;
+
+    // String &operator=(const String &Other)
+    // {
+    //     if (this != &Other)
+    //     {
+    //         delete[] this->m_Data;
+    //         this->m_Data = Other.m_Data;
+    //         this->m_Length = Other.m_Length;
+    //         this->m_Capacity = Other.m_Capacity;
+    //         strdbg("String assigned: \"%s\" (data: %#lx, length: %d, capacity: %d)", this->m_Data, this->m_Data, this->m_Length, this->m_Capacity);
+    //     }
+    //     return *this;
+    // }
+
+    String &operator=(const char *Other)
+    {
+        this->m_Length = strlen(Other);
+        this->m_Capacity = this->m_Length + 1;
+        delete[] this->m_Data;
+        this->m_Data = new char[m_Capacity];
+        strcpy(m_Data, Other);
+        strdbg("String assigned: \"%s\" (data: %#lx, length: %d, capacity: %d)", this->m_Data, this->m_Data, this->m_Length, this->m_Capacity);
+        return *this;
+    }
+
+    String &operator<<(const String &Other)
+    {
+        this->concat(Other);
+        strdbg("String appended: \"%s\" (data: %#lx, length: %d, capacity: %d)", this->m_Data, this->m_Data, this->m_Length, this->m_Capacity);
+        return *this;
+    }
+
+    String &operator<<(const char *Other)
+    {
+        this->concat(Other);
+        strdbg("String appended: \"%s\" (data: %#lx, length: %d, capacity: %d)", this->m_Data, this->m_Data, this->m_Length, this->m_Capacity);
+        return *this;
+    }
+
+    char &operator[](int Index)
+    {
+        strdbg("String index: %d", Index);
+        return this->m_Data[Index];
+    }
+
+    const char &operator[](int Index) const
+    {
+        strdbg("String index: %d", Index);
+        return this->m_Data[Index];
+    }
+
+    bool operator==(const String &Other) const
+    {
+        strdbg("String compared: \"%s\" == \"%s\"", this->m_Data, Other.m_Data);
+        return strcmp(this->m_Data, Other.m_Data) == 0;
+    }
+
+    bool operator!=(const String &Other) const
+    {
+        strdbg("String compared: \"%s\" != \"%s\"", this->m_Data, Other.m_Data);
+        return strcmp(this->m_Data, Other.m_Data) != 0;
+    }
+
+    bool operator==(const char *Other) const
+    {
+        strdbg("String compared: \"%s\" == \"%s\"", this->m_Data, Other);
+        return strcmp(this->m_Data, Other) == 0;
+    }
+
+    bool operator!=(const char *Other) const
+    {
+        strdbg("String compared: \"%s\" != \"%s\"", this->m_Data, Other);
+        return strcmp(this->m_Data, Other) != 0;
+    }
+
+    class Iterator
+    {
+    private:
+        char *m_Pointer;
+
+    public:
+        Iterator(char *Pointer) : m_Pointer(Pointer) {}
+
+        Iterator &operator++()
+        {
+            ++this->m_Pointer;
+            strdbg("String iterator incremented: %#lx", this->m_Pointer);
+            return *this;
+        }
+
+        char &operator*()
+        {
+            strdbg("String iterator dereferenced: %#lx", this->m_Pointer);
+            return *this->m_Pointer;
+        }
+
+        bool operator!=(const Iterator &Other) const
+        {
+            strdbg("String iterator compared: %#lx != %#lx", this->m_Pointer, Other.m_Pointer);
+            return this->m_Pointer != Other.m_Pointer;
+        }
+
+        bool operator==(const Iterator &Other) const
+        {
+            strdbg("String iterator compared: %#lx == %#lx", this->m_Pointer, Other.m_Pointer);
+            return this->m_Pointer == Other.m_Pointer;
+        }
+    };
+
+    Iterator begin()
+    {
+        strdbg("String iterator begin: %#lx", this->m_Data);
+        return Iterator(this->m_Data);
+    }
+
+    Iterator end()
+    {
+        strdbg("String iterator end: %#lx", this->m_Data + this->m_Length);
+        return Iterator(this->m_Data + this->m_Length);
+    }
+};
+
+#endif // !__FENNIX_KERNEL_STRING_H__