In C/C++ sizeof() operator is used to find size of a date type or variable. Expressions written in sizeof() are never executed.
Examples:
// C program to demonstrate that the // expressions written in sizeof() are // never executed #include <stdio.h> int main(){
// The printf in sizeof is not executed
// Only the return type of printf is
// considered and its size is evaluated
// by sizeof,
int a = sizeof ( printf ( "hey" ));
printf ( "%d" , a);
return 0;
} |
Output: 4
Even if we assign a value inside sizeof(), the changes are not reflected.
// One more C program to demonstrate that // the expressions written in sizeof() are // never executed #include <stdio.h> int main() {
int a = 5;
int b = sizeof (a = 6);
printf ( "a = %d, b = %d\n" , a, b);
return 0;
} |
Output: a = 5, b = 4