string functions

#include <stdio.h>

#include<string.h>

int main()

{

    char s1[50]="hello";

    char s2[50]="hero";

    printf("%d\n",strlen(s1));

    printf("%d\n",strlen(s2));

    printf("%s\n",strcat(s1,s2));

//printf("%s\n",strcpy(s2,s1));

printf("%d\n",strcmp(s1,s2));

}