Java, Collection constructor

Question

is there any difference between :

TreeMap myMap = new TreeMap<>();

and

TreeMap

        

Answer 1

They are the same in java 7 where the diamond operator <> was introduced. In older versions of java the diamond operator will not work.

The diamond operator brings type inference to constructors. Type inference on generic methods is available in java 5 and higher. Prior to java 7, to create a generic class using the compiler's type inference you had to use generic factory methods like static <K,T> Map<K,T> createMap().

Answer 2

No difference at all..! Its just a language construct. <> is newly introduced operator known as diamond operator from java 7.

Answer 3

First one will only work in Java 7, the second one from Java 5+