How to merges strings in c

To concatenate strings in C, you can use the strcat function

/*
concat strings in C language
*/

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

int main(int argc, char *argv[]) {
    char str[20] = "Hello ";
    strcat(str, "World!");
    printf("New String: %s\n", str);
    return 0;
}