Ace Programming

Question

What is the output of the following C program?
 

main()
{
    printf("%d%d%d", sizeof('3'), sizeof("3"), sizeof(3));
}

a) 111.     b)222      c)666      d)333

Comments

and it includes NULL too

---

If a size of 1 B is assumed for char then shouldn't sizeof('3') return 1 ?

---

If a size of 1 B is assumed for char then shouldn't sizeof('3') return 1 ?

 

read the comments carefully 

Answer 1

In C sizeof character literal is same as sizeof int. So, it will take 4B.

In C, the type of a character constant like 'a' is actually an int, with size of 4 (or some other implementation-dependent value). In C++, the type is char, with size of 1. This is one of many small differences between the two languages. https://stackoverflow.com/questions/2172943/size-of-character-a-in-c-c

There are some difference between sizeof and strlen.

Sizeof searches for NULL character and counts the number of elements before NULL character, while strlen returns number of character includind NULL.

So, that is why "a" returns 2

strlen() searches for that NULL character and counts the number of memory address passed, So it actually counts the number of elements present in the string before the NULL character, here which is 8.
sizeof() operator returns actual amount of memory allocated for the operand passed to it. Here the operand is an array of characters which contains 9 characters including Null character and size of 1 character is 1 byte. So, here the total size is 9 bytes.

https://www.geeksforgeeks.org/difference-strlen-sizeof-string-c-reviewed/ 

 Atlast sizeof(3) is an integer, which returns sizeof integer i.e.4

Comments

size of character = 1 and size of int =4 or 2 Bytes in C

but the in c,type of character literal is int

where 'a' is a character literal it gives the size same as int

---

sizeof(char)=sizeof('a')=1

what is difference between character literal and sizeof(char)??

I got both same

https://stackoverflow.com/questions/433895/why-are-c-character-literals-ints-instead-of-chars

---

oh yes

sizeof(char)=1

sizeof('a')=4

#include <stdio.h>
 
int main()
{
    printf("%d%d%d", sizeof('3'), sizeof(char), sizeof(3));
	return 0;
}

Moreover here character promotion taking place