java value types

Question

Why its 5? Can you please explain for me?

public class MyClass {
public static void main(String[ ] args) {
int x = 5;
addOneTo(x);
System.out.println(x);
}
static void addOneTo(int num) {
num = num + 1;
}
}
// Outputs "5"

Answer 1

Functions arguments are passed by value, so when addOneTo increments 'num', in fact, it doesn't increment the actual value of 'x'. It remains unchanged, so the output is 5.

Answer 2

this returns to "pass by value" subject in java fundamentals concepts, that is when you pass a variable to a method, just a copy of that variable passed to the method and the variable doesn't change after runing the method ;)
read more about this!

Answer 3

the variable you set in MyClass is 'x' is passed through addOneTo but it's a local variable there.
Also inside addOneTo method 'num' variable is local variable there and after increased to 6 it will be destroyed since there isn't any return value.