C – strlen() function

• strlen( ) function in C gives the length of the given string. Syntax for strlen( ) function is given below.

size_t strlen ( const char * str );

• strlen( ) function counts the number of characters in a given string and returns the integer value.
• It stops counting the character when null character is found. Because, null character indicates the end of the string in C.

Example program for strlen() function in C:

• In below example program, length of the string “computerscience” is determined by strlen( ) function as below. Length of this string 17 is displayed as output.

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

int main( )
{
    int len;
    char array[20]="computerscience" ;

    len = strlen(array) ;

    printf ( "\string length  = %d \n" , len ) ;
    return 0;
}

Output:

string length = 15