CODEWITHSUNDEEP
java
Adrija
Adrija

Reputation: 99

Choosing functions randomly in Java

I want to choose a function randomly. This is the following code:

public class Thank_you_five implements RandomInterface
{
  public static void Thankyou_five(){...}
}
public class Thank_you_four implements RandomInterface
{
  public static void Thankyou_four(){...}
}
public class Thank_you_three implements RandomInterface
{
  public static void Thankyou_three(){...}
}
public interface RandomInterface
{
  public static void Thankyou_five();
  public static void Thankyou_four();
  public static void Thankyou_three();
}

So my goal here is to pick a function randomly, like in python we random.choose() and some function inside, I want to achieve the same with Java

Please help.

Thanks, Adrija

Upvotes: 1

Views: 2226

Answers (2)

paulsm4
paulsm4

Reputation: 121669

Frankly, I like Ruslan's suggestion better. But as long as you ask, this is along the lines of what I was thinking:

package com.example;

import java.util.Random;

public abstract class RandomFn {

    public static RandomFn factory() throws Exception {
        int r = new Random().nextInt(3);
        switch (r) {
           case 0: return new ThankYouOne();
           case 1: return new ThankYouTwo();
           case 2: return new ThankYouThree();
           default : throw new Exception ("ThankYou(" + r +"): unsupported value!");
        }
    }

    public abstract void thankYou();

    public static void main(String[] args) {
        try {
            RandomFn.factory().thankYou();
        } catch (Exception e) {
            System.out.println(e);
        }
    }

}

class ThankYouOne extends RandomFn {
    public void thankYou() {
        System.out.println("Thank you one");
    }
}

class ThankYouTwo extends RandomFn {
    public void thankYou() {
        System.out.println("Thank you two");
    }
}

class ThankYouThree extends RandomFn {
    public void thankYou() {
        System.out.println("Thank you three");
    }
}

If you don't like the idea of many classes, then

public class RandomFn {

    public void thankYou () throws Exception {
        int r = new Random().nextInt(3);
        switch (r) {
           case 0: 
             thankYouOne(); break;
           case 1: 
             thankYouTwo(); break;
           case 2: 
             thankYouThree(); break;
           default : 
             throw new Exception ("ThankYou(" + r +"): unsupported value!");
        }
    }

    private void thankYouOne() { System.out.println("Thank you one"); }

    private void thankYouTwo() { System.out.println("Thank you two"); }

    private void thankYouThree() { System.out.println("Thank you three"); }
    ...

Upvotes: 2

Ruslan
Ruslan

Reputation: 6290

First of all it would be probably better to define one abstarct method inside interface:

public interface RandomInterface{
    void thankYou();
}

Then you can create several implementations:

RandomInterface t1 = () -> System.out.println("thank you 1");
RandomInterface t2 = () -> System.out.println("thank you 2");
RandomInterface t3 = () -> System.out.println("thank you 3");

To get random implementation you can add all objects to array and generate random index:

RandomInterface[] arr = {t1, t2, t3};
int i = new Random().nextInt(arr.length);
arr[i].thankYou();

Upvotes: 7

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