How does java.util.Map's getOrDefault() work?

Question

I noticed that if I do map.getOrDefault(\"key1\", new Object()), even if object is present for key1 in the map, new Object() is created. Though it is n

Answer 1

All the arguments to a function are evaluated before the function is executed. Java needs to evaluate new Empl("dumnba") so it can pass the result into getOrDefault. It can't know before getOrDefault is called that one of the arguments is not going to be required.

If you want to provide a default that is not computed unless needed, you can use computeIfAbsent. For this, you pass in a function, and that function is only executed if the default value is required.

map.computeIfAbsent("1", key -> new Empl("dumnba"))