strstr() function in C ? With Example

 strstr() function in C

The strstr() function returns pointer to the first occurrence of the matched string in the given string. It is used to return substring from first match till the last character.

Syntax:

c
char *strstr(const char *haystack, const char *needle);

a. haystack: This is a pointer to the null-terminated string to be searched.
b. needle: This is a pointer to the null-terminated string containing the sequence of characters to match.

The function returns a pointer to the first occurrence of the substring needle in the string haystack. If the substring is not found, it returns a null pointer.

Example

c
#include <stdio.h> 
#include <string.h> 
int main() { 
const char *haystack = "Hello, World! This is a simple example.";
const char *needle = "World";
char *result = strstr(haystack, needle); 
if (result != NULL) {
printf("'%s' found at position %ld in '%s'\n", needle, result - haystack, haystack);
 } else { 
printf("'%s' not found in '%s'\n", needle, haystack);
 } 
return 0; 
}

In this example, strstr() is used to search for the substring "World" in the string "Hello, World! This is a simple example." If the substring is found, it prints its position; otherwise, it prints a message indicating that the substring was not found.