Some basic java Questions

Question

class overload
void test (long a)
System.out.print("\n\t\t Inside Integer..."+a);
class usetest
public static void main(String args[])
overload ob=new overload();
double i=88;
int j=54;
//ob.test(i); this do not work
ob.test(j); // works
The one that do not work when typecasted works why? When method having same parameter is not present what java compiler do?

Answer 1

The compiler will automatically perform a "widening" cast for you, i.e.
a cast from one type to another where no precision is lost. If you supply
an int and a long is wanted, the int will be cast to a long type.
Not so from double to long because that isn't a widening cast, it's a
"narrowing" cast because bits might get lost after casting. You have
to cast that double to a long explicitly, thereby telling the compiler that
you know what you're doing.
kind regards,
Jos