Map putAll overrides or adds?

Question

When i use the .putAll() will another .putAll() override the content of the map? Will my map contain SomeOfMyObjects and SomeOfMyObjects?

Map<MyObject> blah = new HashMap<>();
blah.putAll('SomeOfMyObjects')
blah.putAll('SomeOfMyObjects')

Thanks!

Answer 1

If you see docs

Copies all of the mappings from the specified map to this map (optional operation). The effect of this call is equivalent to that of calling put(k, v) on this map once for each mapping from key k to value v in the specified map.

this call is equivalent to that of calling put(k, v) 

And for as per put() method

Associates the specified value with the specified key in this map (optional operation). If the map previously contained a mapping for the key, the old value is replaced by the specified value. (A map m is said to contain a mapping for a key k if and only if m.containsKey(k) would return true.)

Answer 2

Not sure if anyone else finds the advice above opposing. But as a new Jenkins/Groovy user, I had to test it for myself to validate and can confirm it overwrites for "put" and "putAll".

        LinkedHashMap test = [X: 1]
        test.put("X", 2)
        assertTrue(test["X"] == 2)

and

        LinkedHashMap test = [X: 1]
        LinkedHashMap test2 = [X: 2]
        test.putAll(test2)
        assertTrue(test["X"] == 2)