What will be the output of the program?

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

int main()
{
    char str[] = "India\0\CURIOUSTAB\0";
    printf("%d\n", strlen(str));
    return 0;
}

Step 1: char str1[] = "Hello"; The variable str1 is declared as an array of characters and initialized with a string "Hello".

Step 2: char str2[] = "Hello"; The variable str2 is declared as an array of characters and initialized with a string "Hello".

We have use strcmp(s1,s2) function to compare strings.

Step 3: if(str1 == str2) here the address of str1 and str2 are compared. The address of both variable is not same. Hence the if condition is failed.

Step 4: At the else part it prints "Unequal".

Step 1: char str1[20] = "Hello", str2[20] = " World"; The variable str1 and str2 is declared as an array of characters and initialized with value "Hello" and " World" respectively.

Step 2: printf("%s\n", strcpy(str2, strcat(str1, str2)));

=> strcat(str1, str2)) it append the string str2 to str1. The result will be stored in str1. Therefore str1 contains "Hello World".

=> strcpy(str2, "Hello World") it copies the "Hello World" to the variable str2.

Hence it prints "Hello World".

A string is a collection of characters terminated by '\0'.

Step 1: char str[] = "India\0\CURIOUSTAB\0"; The variable str is declared as an array of characters and initialized with value "India"

Step 2: printf("%s\n", str); It prints the value of the str.

The output of the program is "India".

gets() gets collects a string of characters terminated by a new line from the standard input stream stdin.

The gets(str1) read the input string from user and store in variable str1.

The gets(str2) read the input string from user and store in variable str2.

The code i = strcmp(str1, str2); The strcmp not only returns -1, 0 and +1, but also other negative or positive values. So the value of i is "unpredictable integer value".

printf("%d\n", i); It prints the value of variable i.

printf("India", "CURIOUSTAB\n"); It prints "India". Because ,(comma) operator has Left to Right associativity. After printing "India", the statement got terminated.

Step 1: char *names[] = { "Suresh", "Siva", "Sona", "Baiju", "Ritu"}; The variable names is declared as an pointer to a array of strings.

Step 2: int i; The variable i is declared as an integer type.

Step 3: char *t; The variable t is declared as pointer to a string.

Step 4: t = names[3]; names[3] = names[4]; names[4] = t; These statements the swaps the 4 and 5 element of the array names.

Step 5: for(i=0; i<=4; i++) printf("%s,", names[i]); These statement prints the all the value of the array names.

Hence the output of the program is "Suresh, Siva, Sona, Ritu, Baiju".