Advantages of Using Double Braces

There are some simple advantages of using double braces:

• Fewer lines of code compared to the native way of creation and initialisation
• The code is more readable
• Creation initialization is done in the same expression

Disadvantages of Using Double Braces

Disadvantages of using double braces are:

• Obscure, not widely known way to do the initialization
• It creates an extra class every time we use it
• Doesn’t support the use of the “diamond operator” – a feature introduced in Java 7
• Doesn't work if the class we are trying to extend is marked final
• Holds a hidden reference to the enclosing instance, which may cause memory leaks

It's due to these disadvantages that double brace initialization is considered as an anti-pattern.