totn C Functions

C Language: strcat function
(String Concatenation)

In the C Programming Language, the strcat function appends a copy of the string pointed to by s2 to the end of the string pointed to by s1. It returns a pointer to s1 where the resulting concatenated string resides.

Syntax

The syntax for the strcat function in the C Language is:

char *strcat(char *s1, const char *s2);

Parameters or Arguments

s1
A pointer to a string that will be modified. s2 will be copied to the end of s1.
s2
A pointer to a string that will be appended to the end of s1.

Returns

The strcat function returns a pointer to s1 (where the resulting concatenated string resides).

Required Header

In the C Language, the required header for the strcat function is:

#include <string.h>

Note

  • Use the strcat function with caution as it is easy to concatenate more bytes into your variable using the strcat function, which can cause unpredictable behavior.

Applies To

In the C Language, the strcat function can be used in the following versions:

  • ANSI/ISO 9899-1990

strcat Example

Let's look at an example to see how you would use the strcat function in a C program:

/* Example using strcat by TechOnTheNet.com */

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

int main(int argc, const char * argv[])
{
   /* Define a temporary variable */
   char example[100];

   /* Copy the first string into the variable */
   strcpy(example, "TechOnTheNet.com ");

   /* Concatenate the following two strings to the end of the first one */
   strcat(example, "is over 10 ");
   strcat(example, "years old.");

   /* Display the concatenated strings */
   printf("%s\n", example);

   return 0;
}

When compiled and run, this application will output:

TechOnTheNet.com is over 10 years old.

Similar Functions

Other C functions that are similar to the strcat function: