Nested Java methods

Question

Earlier in my code I call the method

public static boolean divides(int num, int denom)
{
    if (num%denom==0)
       return true;
    else return false; 
}

Later I am calling the method

public static boolean isLeapYear(int year)

I want to call divides in isLeapYear. Do I have to define divides all over again? Right now I have

public static boolean isLeapYear(int year)
{
public static boolean divides(int num, int denom)
{
   if (divides.class == true && (year%400 ==0) || ((year%4==0) 
       && (year%100 !=0)));
       return true;
       else return false;
}

}

And I get the error that divides is already defined, but when I don't put the whole public static etc. statement in there it wonders what divides is.

I'm also getting a host of other errors (such as it not being able to find year's type after I nest divides), but that's not the main one.

Object Orientation... [Edit] Nvm, but how about just calling divides instead of redefining it? — kutschkem, May 10 '13 at 13:34
java doesn't allow to use nested method declaration http://stackoverflow.com/questions/2634328/can-methods-in-java-be-nested-and-what-is-the-effect — slisnychyi, May 10 '13 at 13:38

score 5 · Accepted Answer · answered May 10 '13 at 13:36

5

You cannot nest method declarations. However, you can simply define them separately and call one from the other. That is the purpose of functions.

public static boolean divides(int num, int denom)
{
    if (num%denom==0)
       return true;
    else return false; 
}

public static boolean isLeapYear(int year)
{
    return divided(x, y);  // not sure what you are trying to divide, but fill in x and y.
}

answered May 10 '13 at 13:36

Brandon

9,822
3
27
37

2

I guess he wants `return divided(year, 4) && (!divided(year, 100) || divided(year, 400))` – Goodwine May 10 '13 at 13:41

PermGenError · Answer 2 · 2013-05-10T13:58:47.573

1

No, you cannot have nested methods in java. what you could do is make a call to divide() from your isLeapYear() method, passing the respective arguments to it.

public static boolean isLeapYear(int year)
{
divides(1, 2);
return result;
}

edited May 10 '13 at 13:58

answered May 10 '13 at 13:33

PermGenError

45,977
8
87
106

What do you mean by passing the respective arguments? – Alex May 10 '13 at 13:37
can the downvoter explain ??, am i missing somethign here ?? – PermGenError May 10 '13 at 13:57
@PermGenError I find your answer lacking feels for the OP, it's obvious that he doesn't know what he is doing and your answer would still be hard for him to understand. – Goodwine May 10 '13 at 14:14
@Goodwine so, you just downvote it ??, you seem to be new to SO. it doesn't work like that here. you only get to d/v if the answer is wrong. – PermGenError May 10 '13 at 14:16
@PermGenError when I hover, it says "This answer is not useful", and that's how I felt. – Goodwine May 10 '13 at 14:21

score 1 · Answer 3 · edited May 10 '13 at 14:02

1

First you cannot declare nested methods.

Anyways you don't need to declare divides again.. If it's defined as static try to call it ContainingClass.divides(x,y);

And what's that divide.class thing?

edited May 10 '13 at 14:02

Mike

47,263
29
113
177

answered May 10 '13 at 13:36

Filipe Roxo

622
3
10

Marco Forberg · Answer 4 · 2013-05-10T14:31:52.650

1

i think you just want to call your method ...

public static boolean divides(int num, int denom)
{
    return (num % denom == 0); 
}

public static boolean isLeapYear(int year)
{
   return (divides(year, 4) && (!divides(year, 100) || divides(year, 400));
}

if the code in your if-else-statements simply return the result of your condition you can shorten your code a bit by returning the condition directly

edited May 10 '13 at 14:31

answered May 10 '13 at 13:41

Marco Forberg

2,634
5
22
33

1

wouldn't inverting the order of `divides(year, 400) || !divides(year, 100)` to `!divides(year, 100) || divides(year, 400)` make it faster? – Goodwine May 10 '13 at 13:43
@Goodwine right. since ´!divides(year, 100)` will be true more often than `divides(year, 400)` chances will be higher that `divedes` is only called twice. I'll edit that. – Marco Forberg May 10 '13 at 13:54
now you have `!divides(year, 400)` ;) (the `!`) – Goodwine May 10 '13 at 14:27
*sigh* corrected that. thx. TGIF... – Marco Forberg May 10 '13 at 14:32

Nested Java methods

4 Answers4