C String Test

Syntax

#include <string.h>

char* strstr(const char* str1, const char* str2);

Example

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

int main () {

   const char str1[] = "The quick brown fox jumps over the lazy dog";
   const char str2[] = "brown";

   char* result = strstr(str1, str2);

   if (result) {
      printf("The substring is: %s\n", result);
   }
   else {
      printf("Substring not found\n");
   }

   return 0;
}

Output

The output of the above example will be:

The substring is: brown fox jumps over the lazy dog

Explanation

The strstr() function is used to search for a substring in a given string. It takes two arguments: str1 is the string to be searched, and str2 is the substring to search for. If the substring is found, a pointer to the first occurrence of the substring in the string is returned. If the substring is not found, a null pointer is returned.

Use

The strstr() function is commonly used to search for a specific word or token in a string. It can be used in a variety of applications, such as parsing command-line arguments, searching for keywords in a document, or filtering data.

Important Points

• The strstr() function returns a pointer to the first occurrence of the substring if it is found.
• The strstr() function is case-sensitive.
• If the substring is not found, a null pointer is returned.

Summary

The C strstr() function is a useful tool for searching for substrings in strings. It returns a pointer to the first occurrence of a substring in a given string. Its versatility and ease of use make it a popular choice for a variety of applications, from text processing to data filtering. Understanding the basic syntax and behavior of this function is an important part of developing C programming skills.