Date: 2012sep23 Update: 2025jul13 Language: Java Keywords: init Q. Java: How to initialize a HashSet A. Here is a nice way to do it:

HashSet<String> shopping_list = new HashSet<String>() {{ add("milk"); add("peanut butter"); add("bread"); }}; // Notice the double bracebrackets

Some people don't like the double brace brackets because it creates an anonymous inner class. But I like it because its compact.