C strcasecmp() Function

Posted in C Tutorial

Updated on Jan 18, 2024

By Mari Selvan

👁️ 423 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In C programming, comparing strings is a common operation, and there are standard functions for this task.

However, for case-insensitive string comparison, the standard library provides strcasecmp() in POSIX systems and _stricmp() in Windows.

In this tutorial, we'll focus on the strcasecmp() function and explore its usage and functionality.

💡 Syntax

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

Syntax

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int strcasecmp(const char *s1, const char *s2);

This function takes two strings, s1 and s2, and performs a case-insensitive comparison.

📄 Example

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

strcasecmp.c

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#include <stdio.h>
#include <strings.h>

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

  // Compare strings case-insensitively
  int result = strcasecmp(str1, str2);

  // Output the result
  if (result == 0) {
    printf("The strings are equal.\n");
  } else {
    printf("The strings are not equal.\n");
  }

  return 0;
}

💻 Output

Output

The strings are equal.

🧠 How the Program Works

In this example, the strcasecmp() function compares the strings "Hello, World!" and "hello, world!" case-insensitively and prints the result.

↩️ Return Value

The strcasecmp() function returns an integer less than, equal to, or greater than zero if s1 is found, respectively, to be less than, to match, or be greater than s2. The comparison is case-insensitive.

📚 Common Use Cases

The strcasecmp() function is particularly useful when you need to compare strings in a case-insensitive manner. It simplifies tasks such as sorting strings or searching for a specific string regardless of case.

📝 Notes

Ensure that your compiler and system support the strcasecmp() function. In Windows environments, consider using _stricmp() instead.

🎢 Optimization

The strcasecmp() function is optimized for case-insensitive string comparison. However, for performance-critical applications, you may want to explore alternative approaches or consider implementing your optimized version based on specific requirements.

🎉 Conclusion

The strcasecmp() function in C is a valuable tool for case-insensitive string comparison. It provides a standardized and efficient way to perform this task, enhancing the flexibility and readability of your code.

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