<string.h> Functions

C strcat()

The function definition of strcat() is:

char *strcat(char *destination, const char *source)

It is defined in the string.h header file.

strcat() arguments

As you can see, the strcat() function takes two arguments:

destination - destination string
source - source string

The strcat() function concatenates the destination string and the source string, and the result is stored in the destination string.

Example: C strcat() function

#include <stdio.h>
#include <string.h>
int main() {
   char str1[100] = "This is ", str2[] = "programiz.com";

   // concatenates str1 and str2
   // the resultant string is stored in str1.
   strcat(str1, str2);


   return 0;


This is programiz.com

Note: When we use strcat(), the size of the destination string should be large enough to store the resultant string. If not, we will get the segmentation fault error.

Did you find this article helpful?