Monday, May 7, 2012

What is Double Brace initialization in Java?


What is Double Brace initialization syntax in Java?



Source: Tips4all

5 comments:

  1. Note that an effect of using this double brace initialisation is that you're creating anonymous inner classes. The created class has an implicit this pointer to the surrounding outer class. Whilst not normally a problem, it can cause grief in some circumstances e.g. when serialising, and it's worth being aware of this.

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  2. For a fun application of double brace initialization, see here Dwemthy’s Array in Java.

    An excerpt

    private static class IndustrialRaverMonkey
    extends Creature.Base {{
    life = 46;
    strength = 35;
    charisma = 91;
    weapon = 2;
    }}

    private static class DwarvenAngel
    extends Creature.Base {{
    life = 540;
    strength = 6;
    charisma = 144;
    weapon = 50;
    }}


    And now, be prepared for the BattleOfGrottoOfSausageSmells and … chunky bacon!

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  3. It's - among other uses - a shortcut for initializing collections. Learn more ...

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  4. This would appear to be the same as the with keyword so popular in flash and vbscript. It's a method of changing what this is and nothing more.

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  5. you mean something like this?

    List<String> blah = new ArrayList<String>(){{add("asdfa");add("bbb");}};


    it's an array list initialization in creation time (hack)

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