CODEWITHSUNDEEP
javaswitch-statementcase
Jason S
Jason S

Reputation: 189836

final public static ints can't be used in a switch statement?

I'm confused. The following code has errors ("..." represents elided code):

int byteOrder = ...;
switch (byteOrder)
{
    case HDF5Constants.H5T_ORDER_BE:
        return ByteOrder.BIG_ENDIAN;
    ...
}

The error is on the case statement and Eclipse complains "case expressions must be constant expressions". I looked in the source file for this and it has a long list of lines like this:

final public static int H5T_ORDER_BE = H5.J2C( JH5T_ORDER_BE );

I thought you could use final public static int constants as cases in a switch statement. Am I wrong???

Upvotes: 3

Views: 1338

Answers (2)

Vinay Sajip
Vinay Sajip

Reputation: 99485

From what you've shown H5T_ORDER_BE is not a compile-time constant (which it needs to be) - it's evaluated at runtime during the initialisation of the class. If it evaluated to a constant such as 123 (rather than what appears to be a static method call) then the compiler wouldn't complain.

Upvotes: 10

Ben M
Ben M

Reputation: 22492

You are wrong! :-)

Case statements can refer only to constants. A static variable is initialized at runtime, so it can't be used here.

Upvotes: 7

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