Is a "char" guy really a size 1?

Question

I always knew that a char is the only type that has fixed size by specification. Its size is 1, no matter the architecture.

But I came across sizeof('a') returning 4 and not 1.

How is that? I learned wrong?

Answer 1

You have learned by half. In fact when you ask sizeof of a variable to type char, or the type itself char, the result will always be 1. It will never change, so there is no reason to use an expression to get its size. Use literal 1 and that’s it.

It can say "through doubts", "through conscience", "will one day change". It will not change, language specification cannot change because someone wanted to. Programming cannot be based on beliefs. It has the right and the wrong. At most, style can have taste. If you like to use sizeof(char) I can only regret it because it’s taste. But to think that it may not be 1 is nonsense.

In fact if you make a sizeof of a literal character will result in the size of a int. For me it was a language error to specify this and I see no use. Nor use this form, no need, use 1.

It is so wrong that C++ thought it best to make it incompatible and the language results in 1 even.

In C:

#include <stdio.h>

int main() {
    char a = 'a';
    printf("%d\n", sizeof(char));
    printf("%d\n", sizeof(a));
    printf("%d\n", sizeof('a'));
}

Behold working in the ideone. And in the repl it.. Also put on the Github for future reference.

In C++

#include <iostream>
using namespace std;

int main() {
    char a = 'a';
    cout << sizeof(char) << "\n";
    cout << sizeof(a) << "\n";
    cout << sizeof('a')  << "\n";
}

Behold working in the ideone. And in the repl it.. Also put on the Github for future reference.