strcat() Function in C: Concatenating Strings

strcat( ) function in C language concatenates two given strings. It concatenates source string at the end of destination string. Syntax for strcat( ) function is given below.

Syntax

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

Parameters

strng1- this is a string(Like: "hi") strng2- this is a string(Like: "hello")

Returns

This function concatenates the source string at the end of the target string. For example, "Hi" and "Hello" on concatenation would result into a string "HiHello".

Program 1

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

int main( )
{
   char strng1[ ] = "Hello " ;
   char strng2[ ]= "Hi" ;

   printf ( "\nSource string = %s", strng1 ) ;
   printf ( "\nTarget string = %s", strng2 ) ;

   strcat(strng1, strng2) ;

   printf("\nTarget string after strcat() = %s \n", strng1) ;
}

Output

Source string = Hello
Target string = Hi
Target string after strcat() = Hello Hi
Press any key to continue . . .

Program 2

#include<stdio.h>
#include<string.h>
void main( )
{
char source[ ] = "Don!" ;
char target[30] = "I am " ;
strcat ( target, source ) ;
printf ( "\nsource string = %s", source ) ;
printf ( "\ntarget string = %s \n", target ) ;
}

Output

source string = Don!
target string = I am Don!
Press any key to continue . . .

Note that the target string has been made big enough to hold the final string.