Question

Explain strlen() and strcat() with syntax and example in c​

Answer 1

Answer:

In C programming, strcat() concatenates (joins) two strings.

The strcat() function is defined in <string.h> header file.

It takes two arguments, i.e, two strings or character arrays, and stores the resultant concatenated string in the first string specified in the argument.

#include <stdio.h>

#include <string.h>

int main()

{

   char str1[] = "This is ", str2[] = "programiz.com";

    //concatenates str1 and str2 and resultant string is stored in str1.

   strcat(str1,str2);

    puts(str1);    

   puts(str2);  

    return 0;

}

strlen()

The function takes a single argument, i.e, the string variable whose length is to be found, and returns the length of the string passed.

The strlen() function is defined in <string.h> header file.

#include <stdio.h>

#include <string.h>

int main()

{

   char a[20]="Program";

   char b[20]={'P','r','o','g','r','a','m','\0'};

   char c[20];

    printf("Enter string: ");

   gets(c);

    printf("Length of string a = %d \n",strlen(a));

    //calculates the length of string before null charcter.

   printf("Length of string b = %d \n",strlen(b));

   printf("Length of string c = %d \n",strlen(c));

    return 0;

}