Question

Possible Duplicate:
Why are C character literals ints instead of chars?
why sizeof('a') is 4 in C?

#include<stdio.h>
int main()
{
  char ch;
  fflush(stdin);
  ch=getchar();
  printf("ch= %d a=%d char=%d", sizeof(ch),sizeof('a'),sizeof(char));
}

I type in ‘a’ (without quotes) as input , and the output I got in my gcc version 4.5.1 is :

ch= 1 a=4 char=1

My question is :

If sizeof(c) is 1 , then how can sizeof('a') be 4 ?

Answer 1

On most of the systems ‘a’== 97, which ASCII value of the character ‘a’.

for e.g:

int i = 97;
char c = i;

If you print the value of variable c with the option ‘%c’ you’ll see ‘a’ on the screen. for your question we can deduce sizeof('a') as sizeof(i) equable to sizeof(97);

You should be able to find this in C standards document.