问题
The program below produces
output - 1 4 4
#include<stdio.h>
void main()
{
char ch;
ch='A';
printf("%d %d %d\n",sizeof(ch),sizeof('A'),sizeof(3.2f));
}
Why is the size of character constant is 4 bytes ?
回答1:
Because according to the C standard the type of a character constant is int, and not char.
So in effect, this is the sizeof(int) on your platform.
回答2:
ch is char type so 1 byte.
'A' is int type so 4 bytes. Because in C the character constant is an int type.
Last is float value so 4 bytes.
These values according to the machine you are using.
Edit -
The range of int and float depends on the machine you are using, 16 bit int is as common as 32 bit int.
来源：https://stackoverflow.com/questions/41549293/why-the-sizeof-character-constant-is-4-bytes