The library function used to find the last occurrence of a character in a string

The library function used to find the last occurrence of a character in a string is

2) What is the output of this C code?

#include <stdio.h>
     #include <string.h>
     int main()
     {
         char *str = "hello, world";
         char str1[9];
         strncpy(str1, str, 9);
         printf("%s %d", str1, strlen(str1));
     }

3) Which is more appropriate for reading in multi-word string?

4) What will be the output of the program ?

 #include<stdio.h>
 int main()
 {
     printf(2+"C Programming MCQ on Study 2 Online\n");
     return 0;
 }

5) What will be the output of the following program?

void main()
 {
       char str1[] = "abcd";
       char str2[] = "abcd";
       if(str1==str2)
             printf("Equal");
       else
             printf("Unequal");
 }