Is sizeof Operator in C Evaluate the Expression for Determining its Size

/* 
 * sizeof_eval_exp.c -- program displays if sizeof evaluates an expression
 * as operand
 */
#include <stdio.h>
int main(void)
{
    int a = 1;
    int arr[10] = {1,2,3,4,5,6,7,8,9,10};
 
    printf("size of int a and value of a in sizeof (a = 5) is %d bytes "
           "%d\n", sizeof (a = 5), a);
 
    printf("size of int a and value of a in sizeof (a++) is %d bytes %d\n",
            sizeof a++, a);
 
    printf("size of arr and value of int arr[5] in sizeof (arr) is %d bytes"
           " %d\n", sizeof (arr), arr[5]);
 
    printf("size of arr and value of int arr[0] in sizeof (arr[0] = 10) is "
           "%d bytes %d\n", sizeof (arr[0] = 10), arr[0]);
 
        return 0;
}

    sizeof unary-expression;    /* any variable, array, structure etc. */
    sizeof (datatype);