methods and returning values
this code comes from my textbook and i don't follow the explanation of it.
in the sub method for example, the variable num gets divided by two, but as far as i can see num has no value, whereas i see the number variable has the value of 25.
can anyone help me with the basics here?
thanks
publicclass ReturnValue
{
publicstaticvoid main(String[] args)
{
int number = 25;
System.out.println(number+" is " +sub(number) );
if( sub2(number) )
System.out.println(number+" is above 10");
}
publicstatic String sub(int num)
{
return (num % 2 == 0) ?"even" :"odd";
}
publicstaticboolean sub2(int num)
{
return (num >10) ?true :false;
}
}
Output
25 is odd
25 is above 10
[1730 byte] By [
mark_8206a] at [2007-11-26 18:01:38]
When one of those methods is called, the "num" variable pops into existence, and is assigned to the value given as an argument to the method.
Note that it's assigned the value of the argument. That means that the value of number -- 25 in this case -- is copied into the "num" variable. So if one of those methods change the value of "num", then the value of the variable "number" is unchanged.
> thanks
> so if there was another variable int x = 22;
> i could let the sub method deal with that too?
> System.out.println(number+ " is " +sub(x) );
>
> is that correct?
Yes, except for that little typo, that is perfectly correct; isn't parameter
passing cute? ;-) You can also pass literal values or entire expressions
if you want:int x= 42;
sub(x/2);
sub2(21);
// etc. etc. etc.
kind regards,
Jos
