How to insert array into hashtable w/o initializing in Java?

Question

I have a hashmap initialized as follows:

Hashmap<String[][], Boolean> tests = new Hashmap<String [][], Boolean>();

I would like to insert into tests without having to initialize the key:

tests.put({{"a"}, {"a"}}, true);

However, Java doesn't seem to let me do this. It works if I do it like this:

String[][] hi = {{"a"}, {"a"}};
tests.put(hi, true);

Is there any way to avoid the latter and get the former working?

Can someone also explain the reasoning behind this error?

Thanks

Answer 1

Yes, you can write like this:

tests.put(new String[][] {{"a"}, {"a"}}, true);

This is often referred to as an anonymous array or a just-in-time array.