Avoid if else statement

Question

I have 50 different classes. I made a generic class(All) with all these 50 classes.

public class All {

    private First first;
    private Second second;
    private Third third;
...


//GETTERS AND SETTERS
}

I have a generic method and inside this I have this piece of code:

 All all=new All();

       String result;
       if(all.getFirst()!=null){
           result=methodA(all.getFirst());
       }
       else if(all.getSecond()!=null){
           result=methodB(all.getSecond());
       }
       else if(all.getThird()!=null){
           result=methodC(all.getThird());
       }
...

I don´t like this configuration because it´s an unreadable code for so many classes.

How can I improve this code?

you need to implement `get(int index)`, in the loop `for` you running for all elements and checking to null — Andrew Tobilko, Jun 24 '15 at 22:18

Andrew Tobilko · Answer 1 · 2016-03-17T17:05:05.530

Maybe the following piece of code is helpful for you:

 All all = new All();

 String result;

 for(int i = 0; i++ < all.length(); ) {
     YourInterface element = all.get(i);
     if(element != null)
         result = method(element);
 }

where,

length() - amount of the classes
get(int index) - access method to element from index
YourInterface - common interface for all your classes

The next step is to use the reflection.

score 1 · Answer 2 · edited May 23 '17 at 12:07

You can definitely clean this up with either Reflection or creating your own version of that. You'd have something like: all.getObjects(); Then have that bounce against a 2 dimensional array to grab the method needed to invoke then call that.

If I'll pop back in later to finish this up. but until then here's some things I found:

using reflection to get objects from collection class

What is reflection and why is it useful?

score 1 · Answer 3 · answered Jun 24 '15 at 23:21

1

String result = all.getFirst() != null ? methodA(all.getFirst())
   : all.getSecond() != null ? methodB(all.getSecond())
   : all.getThird() != null ? methodC(all.getThird())
   : null;

answered Jun 24 '15 at 23:21

Dragan Bozanovic

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Avoid if else statement

3 Answers3