How to creat a set with elements from either set 1 or set 2 or both?-CodePudding

Hey I wanted to ask how I can add elements in a new set that either are in my set a or set b or both sets. This is what I have until now. Would be nice of you could help me.

public static Set<String> vereinigung(Set<String> a, Set<String> b) {
        Set<String> setForAB = new HashSet<String>();

        //add elements from a
        setForAB.add(String.valueOf(a));

        //add elements from a
        setForAB.add(String.valueOf(b));

        //elements from both sets
        setForAB.addAll(a);
        setForAB.addAll(b);

        return setForAB;
    }

CodePudding user response：

You are on right track, removed unncessary code from your solution. This should suffice.

public static Set<String> vereinigung(Set<String> a, Set<String> b) {
        Set<String> setForAB = new HashSet<String>();
        //add elements from both sets
        setForAB.addAll(a);
        setForAB.addAll(b);
        return setForAB;
    }

CodePudding user response：

In Java, Sets can not contain duplicates, so if you want a set C to contain all values from set A and set B, then you simply need to add all elements of A and B. When a duplicate is found, it will simply ignore it and move on. I'm not sure why you are casting your sets to a string, but you can simply add the sets themselves to the new set:

Set<Integer> a = new HashSet<Integer>();
Set<Integer> b = new HashSet<Integer>();
Set<Integer> c = new HashSet<Integer>(a);
c.addAll(b);