C++ String Functions

What You’ll Find Here

C++ gives you two complementary ways to work with text: the modern std::string class with member methods like find(), and classic C-style functions from <cstring> such as strlen(), strcmp(), and strcpy(). This page is your central hub—browse every function in our tutorial series, jump to full guides with examples and output, and learn patterns that work in real C++ programs and interviews.

Introduction

In C++, strings come in two familiar forms. The modern approach uses std::string from <string>—an object that manages its own memory and exposes methods like find(), length(), and substr(). The classic approach uses null-terminated char arrays with free functions from <cstring>: strlen(), strcmp(), strcpy(), and more.

Both styles appear in production code and technical interviews. New projects typically favor std::string, but understanding <cstring> is essential when interfacing with C libraries, reading legacy code, or working with fixed-size buffers.

🚀 Usage Tips

• Prefer std::string in new code — it handles memory, supports + concatenation, and avoids most buffer-overflow pitfalls.
• Check find() with npos — write if (text.find("Java") != std::string::npos) instead of treating the return value as a boolean.
• strcmp() returns a sign, not true/false — zero means equal; negative or positive values indicate ordering. Do not write if (strcmp(a, b)) when you mean “are equal.”
• Size buffers before strcpy/strcat — know the destination capacity and leave room for the null terminator '\0'.
• Use strn* variants for limits — strncpy() and strncat() cap how many characters are copied or appended.
• Read the tutorial — each linked function page includes syntax, five examples, a quick reference table, and FAQs.

📝 How to Call a String Function

C++ string operations follow one of two patterns depending on the style you use:

// Modern std::string (include <string>)
std::string text = "Hello, C++";
size_t pos = text.find("C++");

// C-style cstring (include <cstring>)
const char* word = "Hello";
size_t len = strlen(word);
int cmp = strcmp(word, "Hello");

Common Patterns

std::string vs <cstring>

If you come from Java or Python, think of std::string as the object-oriented string class with built-in methods. The <cstring> functions are lower-level: they operate on raw char* pointers and require you to manage buffer sizes yourself. Many programs use both—std::string for everyday logic, and .c_str() when a C API expects a const char*.

#include <iostream>
#include <string>
#include <cstring>

int main() {
    // Modern: std::string
    std::string greeting = "Hello, World!";
    if (greeting.find("World") != std::string::npos) {
        std::cout << "Found World at index "
                  << greeting.find("World") << "\n";
    }

    // Classic: cstring on a char buffer
    char buffer[32] = "Hello";
    strcat(buffer, ", C++!");
    std::cout << buffer << " (length: " << strlen(buffer) << ")\n";
    return 0;
}