The **`strstr()` function** takes in two strings (strA and strB)​ as arguments, finds the first occurrence of strB in strA and returns a pointer to the first character of this occurrence.

# Code
The code below implements the function above:


#include <iostream>
#include <string.h>

using namespace std;

int main() {

  char strA[] = "A red apple vs a green apple";
  char strB[] = "apple";

  char* p = strstr(strA, strB); // The strstr() function call

  strcpy(p, "strawberry"); // Using the obtained pointer to modify contents of strA

  cout<< strA;
}

What is the strstr() function in C++?

The strstr() function finds and returns a pointer to the first occurrence of one string within another.