How Does sizeof(Array) work

Question

How does c find at run time the size of array? where is the information about array size or bounds of array stored ?

Answer 1

sizeof gives the size of the variable, not the size of the object that you're pointing to (if there is one.) sizeof(arrayVar) will return the array size in bytes if and only if arrayVar is declared in scope as an array and not a pointer.

For example:

char myArray[10];
char* myPtr = myArray;

printf("%d\n", sizeof(myArray)) // prints 10 
printf("%d\n", sizeof(myPtr)); // prints 4 (on a 32-bit machine)