定义int时的sizeof（（int）（float）（char）i））（int）（float）（char）i;

Question

#include<stdio.h>
double i;

int main()
{
    (int)(float)(char) i;
    printf("%d", sizeof((int)(float)(char)i));
    return 0;
}

The above outputs 4 on a Micrsoft compiler. Why?

Answer 1

sizeof is the size, in bytes, of the variable. In this case, i is being cast to an int which is 4 bytes.

These are the sizes of types on MS C++: http://msdn.microsoft.com/en-us/library/cc953fe1(v=vs.71).aspx

Answer 2

The last cast operation is to int, so u will get the sizeOf(int). Integer size differes form compiler to another, some return 2-bytes and onther return 4-bytes.

Answer 3

sizeof something tells you how many bytes it takes up in memory. Your platform and toolchain clearly has 32-bit integers; it's telling you that int , on your toolchain (compiler), takes up 4 bytes.