Check this why is it so?

Question

#include<studio.h>

int main(){
int arr[]={1,2,3,4};
int *ptr=arr;
sizeof(arr);//16
sizeof(ptr);//8
}

Even though both arr and ptr are both pointers why sizeof operator return different values.

Answer 1

*arr* is not a pointer, it is an array whereas *ptr* is a pointer hence the output.

also sizeof operator is operated at compile-time and not runtime that's why sizeof array is known and not sizeof memory block pointing by pointer *ptr*

Answer 2

An array can be implicitly converted into a constant pointer, but it is not a pointer.

Answer 3

Because arr is not a pointer, it's an array
(int[4] not int*)

Answer 4

But they say that name of array is constant pointer