What will be the output of the program?

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

int main()
{
    char sentence[80];
    int i;
    printf("Enter a line of text\n");
    gets(sentence);
    for(i=strlen(sentence)-1; i >=0; i--)
        putchar(sentence[i]);
    return 0;
}

Step 1: void fun(); This is the prototype for the function fun().

Step 2: fun(); The function fun() is called here.

The function fun() gets a character input and the input is terminated by an enter key(New line character). It prints the given character in the reverse order.

The given input characters are "abc"

Output: cba

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".

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

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("%c\n", "abcdefgh"[4]); It prints the 5 character of the string "abcdefgh".

Hence the output is 'e'.

Step 1: char str[25] = "CuriousTab"; The variable str is declared as an array of characteres and initialized with a string "CuriousTab".

Step 2: printf("%s\n", &str+2);

=> In the printf statement %s is string format specifier tells the compiler to print the string in the memory of &str+2

=> &str is a location of string "CuriousTab". Therefore &str+2 is another memory location.

Hence it prints the Garbage value.

It prints 'CuriousTab CuriousTab' in TurboC (in 16 bit platform).

It may cause a 'segmentation fault error' in GCC (32 bit platform).

The function printf() returns the number of charecters printed on the console.

Step 1: char a[] = '\0'; The variable a is declared as an array of characters and it initialized with "\0". It denotes that the string is empty.

Step 2: if(printf("%s", a)) The printf() statement does not print anything, so it returns '0'(zero). Hence the if condition is failed.

In the else part it prints "The string is empty".

In printf("%u %s\n", &"Hello", &"Hello");.

The %u format specifier tells the compiler to print the memory address of the "Hello1".

The %s format specifier tells the compiler to print the string "Hello2".

Hence the output of the program is "1022 Hello2".