C - strcat() function

strcat() is a useful string library function, which concatenates one string to another.

To concatenate is to glue one or more pieces of data together or to connect one or more links together.

Syntax

Following is the syntax of strcat() function:

char *strcat(char *dest, const char *src)

1	char strcat(char dest, const char *src)

Parameters

dest − This is pointer to the destination array, which should contain a C string, and should be large enough to contain the concatenated resulting string.

src − This is the string to be appended. This should not overlap the destination.

Example of strcat()

Let’s see the simple example to concatenate first string with another:

#include<stdio.h>  
#include<string.h>    
int main()
{    
    char ch[20]={'h', 'e', 'l', 'l', 'o', '\0'};    
    char ch2[20]={'w', 'o', 'r', 'l', 'd', '\0'};    
    
    strcat(ch,ch2);    
    
    printf("Value of first string is: %s",ch);    
 
    return 0;    
}

#include<stdio.h>

#include<string.h>

int main()

{

char ch[20]={'h', 'e', 'l', 'l', 'o', '\0'};

char ch2[20]={'w', 'o', 'r', 'l', 'd', '\0'};

strcat(ch,ch2);

printf("Value of first string is: %s",ch);

return 0;

}

When you run above program, the output will be following:

Value of first string is: helloworld

1	Value of first string is: helloworld

String Manipulation Functions

Few commonly used string handling functions are discussed below:

String Functions	Description
strlen()	Calculates the length of string
strcat()	Concatenates(joins) two strings
strncat()	Appends a portion of string to another
strcpy()	Copies a string to another string
strncpy()	Copies number of characters of one string to another
strcmp()	Compares two strings
strncmp()	compares at most the first n bytes of str1 and str2.
strchr()	Returns pointer to first occurrence of char
strrchr()	Return last occurrence of given character in a string is found
strstr()	Returns pointer to the first occurrence of the string
strdup()	Duplicates the string
strndup()	Similar to strdup(), but copies at most n bytes.
strerror()	Returns the error message
strtok()	Tokenizing given string using delimiter
strcoll()	Compares first string with another.