C Programming strchr() Function: Finds a character in a string

strchr is a function in the C standard library used to find the first occurrence of a specified character in a string; this function is similar to the memchr function, except that memchr can be applied to any data type, whereas strchr can only be applied to strings.

strchr Function Header File

The header file for the strchr function is <string.h>. Before using the strchr function, make sure to include this header file in your C code:

#include <string.h>

strchr Function Prototype

char* strchr(const char* s, int c);

The strchr function locates the first occurrence of the character c (converted to char) in the string pointed to by s; the null terminator '\0' is considered part of the string.

Parameters

• s: A pointer to the string to be searched;

• c: The character to be found, which is converted to char type;

Return Value

The memchr function returns a pointer to the located character; if c is not found in the string, it returns a null pointer NULL;

strchr Example Code

Checking if a string contains a space

If the string does not contain a space, strchr() should return NULL;

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

bool contains_space(const char* src) {
    
    if (strchr(src, ' ') == NULL) {
        return false;
    }

    return true;
}

int main() {

    const char* str = "perfcode.com";

    if (contains_space(str)) {
        printf("the string contains a space.\n");
    }
    else {
        printf("the string does not contain a space.\n");
    }

    return 0;
}