C++ String strcmp() Function

Posted in C++ Tutorial

Updated on Jan 15, 2024

By Mari Selvan

👁️ 183 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In C++ programming, comparing strings is a common operation, and the strcmp() function is a standard library function designed for this purpose.

The strcmp() function compares two strings lexicographically.

In this tutorial, we'll explore the usage and functionality of the strcmp() function in C++.

💡 Syntax

The signature of the strcmp() function is as follows:

Syntax

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int strcmp(const char* str1, const char* str2);

This function takes two C-style strings, str1 and str2, and returns an integer value representing their lexicographical relationship.

📄 Example

Let's delve into an example to illustrate how the strcmp() function works.

strcmp.cpp

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#include <iostream>
#include <cstring>

int main() {
  const char * str1 = "Hello, World!";
  const char * str2 = "Hello, C++!";

  // Compare strings lexicographically
  int result = std::strcmp(str1, str2);

  // Output the result
  if (result == 0) {
    std::cout << "The strings are equal." << std::endl;
  } else if (result < 0) {
    std::cout << "str1 is lexicographically less than str2." << std::endl;
  } else {
    std::cout << "str1 is lexicographically greater than str2." << std::endl;
  }

  return 0;
}

💻 Output

Output

str1 is lexicographically greater than str2.

🧠 How the Program Works

In this example, the strcmp() function compares the strings "Hello, World!" and "Hello, C++!" lexicographically and prints the result.

↩️ Return Value

The strcmp() function returns an integer less than, equal to, or greater than zero if str1 is found, respectively, to be less than, to match, or be greater than str2.

📚 Common Use Cases

The strcmp() function is useful when you need to compare strings based on their lexicographical order. It's commonly employed in sorting algorithms, searching algorithms, and other scenarios where string ordering matters.

📝 Notes

The comparison is case-sensitive. For case-insensitive comparison, consider using std::stricmp() or other platform-specific alternatives.
Always ensure that the strings being compared are null-terminated to avoid undefined behavior.

🎢 Optimization

The strcmp() function is optimized for efficient string comparison. For performance-critical applications, consider other alternatives or optimizations based on specific requirements.

🎉 Conclusion

The strcmp() function in C++ is a fundamental tool for lexicographically comparing strings. It provides a standardized and efficient way to perform this task, contributing to the clarity and reliability of your code.

Feel free to experiment with different strings and explore the behavior of the strcmp() function in various scenarios. Happy coding!