How to Check if a String contains given Substring in C - Step by Step Examples

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How to Check if a String contains given Substring in C ?

Answer

To check if a string contains a given substring in C, you can use the 'strstr' function.

✐ Examples

1 Check if a String contains given Substring using 'strstr' function

In this example,

We create a function 'containsSubstring' that takes a string and a substring as input.
We use the 'strstr' function to check if the substring is present in the string.
If the substring is found, a pointer to the first occurrence of the substring is returned; otherwise, 'NULL'.
Finally, we print the result.

C Program

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

char* containsSubstring(char* str, char* substr) {
    return strstr(str, substr);
}

int main() {
    char str[] = "Hello World";
    char substr[] = "World";
    char* contains = containsSubstring(str, substr);
    if (contains) {
        printf("String contains substring '%s'", substr);
    } else {
        printf("String does not contain substring '%s'", substr);
    }
    return 0;
}

Output

String contains substring 'World'

Summary

In this tutorial, we learned How to Check if a String contains given Substring in C language with well detailed examples.