Debug the error and please explain !!

Question

public class MyClass
{
public static void main(String[ ] args)
{
int x = 5;
int y = addOneTo(x);
System.out.println(y);
}

static void addOneTo(int x)
{
x = x + 1;
}
}

Answer 1

your return type for addOneTo method is void but in int y=addOneTo(x); statement you are trying to assign your void type to int type. so error occurs.. To fix it declare addOneTo method as int type

Answer 2

How

Answer 3

static int addOneTo(int x) {
return x + 1;
}

Answer 4

i know the answer but why? why can't we use void type? methods can be of any type..