No way to determine # of bits in basic types

Name: clC74495 Date: 09/10/98


There seems to be no predefined constants in Java for determining the number of bits
in various integral types. For instance, in C, I can #include <limits.h> and then use
constants such as CHAR_BITS to indicate the number of bits in a 'char' value. In Java,
I have to define my own local constant do do something similar, and my own local
constant will almost certainly have a different name from the one used by other Java
developers. Or, I can just hardcode the number, which usually leads to
difficult-to-understand code.

I would like to see constants added to each of the numeric 'wrapper' classes, like so:

class Integer
{
   ...
   public static final BITS = 32;
}
class Byte
{
   public static final int BITS = 8;
}
etc. for classes Long, Short and Char.

This would allow easy writing of code such as:
byte [] bytes = whatever;
int getBitAt(int bitIndex)
{
    return ((bytes[bitIndex / Byte.BITS]
             >> (bitIndex % Byte.BITS)) & 1;
}
rather than encouraging people to write code such as:
int getBitAt(int index)
{
    return (data[x / 8] >> (x % 8)) & 1;
}

As a somewhat seperate issue, it seems to me that this information would also
be useful as a virtual method inherited from class Number.
(Review ID: 38581)
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