C program - 1

Question

#include<stdio.h>
int main(){

short int i=20;
char c=97;
printf("%d %d %d\n",sizeof(i),sizeof(c),sizeof(i+c));

return 0;
}
 

could anyone explian why the answer of sizeof(i+c) is 4 ?

Answer 1

Actually, sizeof operator returns size in bytes and is implementation dependent. Some compilers assign two bytes to int and some four bytes.Characters are internally stored as integers. It seems your integers are stored as 4 bytes.

(i+c) is 4 because 97 is stored as an integer and short is promoted to higher type int berfore addition (97+20) = int so 4 bytes

Comments

I am little confused . As sizes are given , so now u should not talk about compiler .

---

r u sure it works with other data types ?

---

no. sorry.

see this http://www.geeksforgeeks.org/sizeof-operator-c/

Answer 2

If you want that your size of data type remain same in every compiler u can use int8_t (which will allocate 8 bit) and int16_t will allocate 16 bit (2 byte), int32_t will allocate 4 byte (32 bit) .