How to convert SET to array in APEX?

I have map with key and value and my goal is to get list of 'key'. I am thinking to get it to the array or List. Got to the point where I have key values in the SET but haven't figure out how to convert to the array.

below is my code:

Map<String, String> mmm = new Map<String, String>(); mmm.put('one', 'oneee'); mmm.put('two', 'twooo'); mmm.put('three', 'threeee'); mmm.put('four', 'fourff'); //outputs values in the map system.debug('=======values()==========>' + mmm.values()); //outputs key in the map system.debug('=======keyset()===========>' + mmm.keyset()); //get keys in the type SET SET<string> s = mmm.keyset(); //returns 4 system.debug('------------------------------------' + s.size()); s.arrayTo() //this method does not exist :( 

4 Answers

Use List.addAll method?

If not - you could always manually loop through the set...

Could you use:

Set keys = mmm.keySet(); List keyList = new List(keys);

You should always used generics for type safety.

Map<String, String> mmm = new Map<String, String>(); mmm.put('one', 'oneee'); mmm.put('two', 'twooo'); mmm.put('three', 'threeee'); mmm.put('four', 'fourff'); List<String> lstKeys = new List<String>(mmm.keyset()); System.debug('Output : '+lstKeys); 

As per link : .

This solution will work.

A quick and simple way to do this would also be:

new List<String>(mmm.keySet()); //or new String[mmm.keySet()]; 

In some code I wrote recently I've got a Set<String> and am passing it into a method that takes a List<String> with methodName( new List<String>(setVariable) ); or methodName(new String[setVariable] );

Yes I know the post is 11+ years old... but it is also what comes up when searching so I put my answer here.