I was curious, too. Looked it up. Still don't understand tho. >The sizeof in C is an operator, and all operators have been implemented at compiler level; the

I was curious, too. Looked it up. Still don't understand tho. >The sizeof in C is an operator, and all operators have been implemented at compiler level; therefore, you cannot implement sizeof operator in standard C as a macro or function. You can do a trick to get the size of a variable by pointer arithmetic.