strchr in C

Last Updated : 27 May, 2025

The strchr() function in C is a predefined function in the <string.h> library. It is used to find the first occurrence of a character in a string. It checks whether the given character is present in the given string. If the character is found, it returns the pointer to its first occurrence otherwise, it returns a null pointer, indicating the character is not found in the string.

Syntax of strchr() in C

char *strchr(const char *str, int ch);

Parameters of strchr() in C

str: It is the string in which we have to search the character. This string is a constant character pointer, meaning that the function will not modify the string.
ch: It is a character to be searched in the string. Though passed as an int, it represents a character and is cast internally. This allows strchr() to be used with character values, including special characters and ASCII values.

Return Value of strchr()

The strchr() function returns a pointer to the first occurrence of the character in the string. If the character is not found, the function returns NULL. Here, the return type is char *, which allows direct access to the character and subsequent characters in the string from the found position.

Example Programs Using strchr() in C

The following examples illustrates how we can use strchr() in various scenarios.

Example 1:

Using strchr() to check the existence of character in a string and print its first occurrence.

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

int main()
{
    // define a string
    const char* str = "GeeksforGeeks";
    // define a char ch to be searched in str
    char ch = 's';

    // Use strchr to find the first occurrence of the
    // character 's'
    const char* result = strchr(str, ch);

    if (result != NULL) {
        // Calculate the position by subtracting the base
        // pointer from the result pointer
        printf("Character '%c' found at position: %ld\n",
               ch, result - str);
    }
    else {
        printf("Character '%c' not found.\n", ch);
    }

    return 0;
}

Output

Character 's' found at position: 4

Example 2:

Using strchr() function to parse the string until a given delimiter is found.

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

int main()
{
    // Original string containing username and password
    const char* str = "GeeksforGeeks:abc@123";
    // Delimiter to separate username and password

    char delimiter = ':';
    // Find the position of the delimiter in the string
    char* delimiter_position = strchr(str, delimiter);

    // If the delimiter is found in the string
    if (delimiter_position != NULL) {
        // Calculate the length of the username
        size_t username_length = delimiter_position - str;

        // Allocate memory for the username and copy the
        // username part of the string
        char username[username_length + 1];
        strncpy(username, str, username_length);

        // Null-terminate the username string
        username[username_length] = '\0';

        // The password starts right after the delimiter
        char* password = delimiter_position + 1;

        // Print the extracted username and password
        printf("Username: %s\n", username);
        printf("Password: %s\n", password);
    }
    else {
        // If the delimiter is not found, print an error
        // message
        printf("Delimiter not found.\n");
    }

    return 0;
}

Output

Username: GeeksforGeeks
Password: abc@123

strrchr() in C++

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