what is the logic???

Question

when I write code
#include <stdio.h>

int main() {
printf("int: %d \n", sizeof(int));
printf("float: %d \n", sizeof(float));
printf("double: %d \n", sizeof(double));
printf("char: %d \n", sizeof(char));

return 0;
}

output as under:
int: 4
float: 4
double: 8
char: 1
My question is from where the values shown in the output fetched from?

Answer 1

It outputs how much memory variable of each data type takes in bytes.

Answer 2

It is the number of bytes.
int and float use 4 bytes of memory, double uses 8 bytes, and char only need 1 byte of memory.

1 byte = 8 bit (0 or 1)

Answer 3

Read here https://en.m.wikipedia.org/wiki/Sizeof in particular the "implementation" section

Answer 4

This fetched from the pre-processor macro DATATYPE_BIT, defined in the standard include file limits.h file.
And in the above program the size of function returns a long int value but %d is for integer there is a warning in this program.