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javaprimitiveprimitive-types

Does Java define the size of its primitive types anywhere?

Is there a package that defines the size of Java primitives that I can import in my project? I'm doing some manual bit setting and I keep a byte index. I don't want to do currentByte += 4 when I set an int (magic numbers are frowned upon), I rather do currentByte += <SomePackage>.SIZE_OF_INT

I guess I can define my own, but that's kind of clunky, especially if those are available somewhere.

Solution

  • Not a class, but you have Integer.SIZE, and so on for Long and floating point classes too. You also have *.BYTES.

    Therefore Integer.SIZE is 32, Integer.BYTES is 4, Double.SIZE is 64 and Double.BYTES is 8, etc etc; all of these are ints in case you were wondering.

    NOTE: *.BYTES are only defined since Java 8 (thanks @Slanec for noticing)

    (*.SIZE appeared in Java 5 but you do use at least that, right?)

    And yes, this is defined by the JDK since the JLS itself defines the size of primitive types; you are therefore guaranteed that you'll have the same values for these constants on whatever Java implementation on whatever platform.