Tutorials

C strrchr() Function

Posted in C Tutorial

Updated on Nov 16, 2024

By Mari Selvan

👁️ 265 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In the realm of C programming, working with strings is a common and essential task.

The strrchr() function is part of the C Standard Library and is used to find the last occurrence of a character in a given string.

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

💡 Syntax

The strrchr() function has the following signature:

Syntax

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char *strrchr(const char *str, int character);

str: The string in which the search will be performed.
character: The character to be located. This is passed as an integer but is commonly specified as a character literal.

📄 Example

Let's dive into an example to illustrate how the strrchr() function works.

strrchr.c

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#include <stdio.h>
#include <string.h>

int main() {
  const char * text = "Hello, C Programming!";
  char searchChar = 'o';

  // Find the last occurrence of 'o' in the string
  char * result = strrchr(text, searchChar);

  // Output the result
  if (result != NULL) {
    printf("Last occurrence of '%c': %s\n", searchChar, result);
  } else {
    printf("'%c' not found in the string.\n", searchChar);
  }

  return 0;
}

💻 Output

Output

Last occurrence of 'o': ogramming!

🧠 How the Program Works

In this example, the strrchr() function is used to find the last occurrence of the character 'o' in the string "Hello, C Programming!" and then prints the result.

↩️ Return Value

The strrchr() function returns a pointer to the last occurrence of the specified character in the string. If the character is not found, it returns NULL.

📚 Common Use Cases

The strrchr() function is particularly useful when you need to locate the position of the last occurrence of a specific character in a string. It can be used for tasks such as extracting the file extension from a file path or parsing data.

📝 Notes

The character to be located is passed as an integer, but it is typically specified using character literal syntax, such as o.
The function is case-sensitive, so 'o' and 'O' are considered different characters.

🎢 Optimization

The strrchr() function is optimized for efficiency. However, if you know that the character you are searching for is the null terminator \0 or the last character in the string, using other functions like strlen() may provide a faster alternative.

🎉 Conclusion

The strrchr() function in C is a valuable tool for finding the last occurrence of a character in a string. It provides flexibility in string manipulation tasks and is a fundamental component of C string handling.

Feel free to experiment with different strings and characters to deepen your understanding of the strrchr() function. Happy coding!