A cleaner if statement with multiple comparisons [closed]

Question

The following statement just looks very messy when you have a lot of terms:

if(a.equals("x") || a.equals("y") || a.equals("z") || Any number of terms...... )     //Do something 

Is there a cleaner way of performing the same action, I would like my code to be as readable as possible.

NOTE: x, y and z are just placeholders for any string of any length. There could be 20 string terms here of variable length in if condition each being OR'd together

Answer 1

What do you think looks "unclean" about it?

If you have a bunch of complicated boolean logic, you might separate the different parts of it into individual boolean variables and refer to them in the if statement.

Or you could create a function that takes your 'a' variable and returns a boolean. You'd just be hiding your logic in the method, but it would clean up your if statement.

Answer 2

Set<String> stuff = new HashSet<String>(); stuff.add("x"); stuff.add("y"); stuff.add("z"); if(stuff.contains(a)) {     //stuff } 

If this is a tight loop you can use a static Set.

static Set<String> stuff; static {     stuff = new HashSet<String>();     stuff.add("x");     stuff.add("y");     stuff.add("z"); }  //Somewhere else in the cosmos  if(stuff.contains(a)) {     //stuff } 

And if you want to be extra sure nothing is getting modified while you're not looking.

Set<String> test = Collections.unmodifiableSet(new HashSet<String>() {         {             add("x");             add("y");             add("z");         }     }); 

If you just want to get some logic in there for a handful of hard coded conditions then one of the switch or if statement with newlines solutions might be better. But if you have a lot of conditions then it might be good to separate your configuration from logic.