Question

I’m trying to write a piece of code that takes in a two digit hex number, e.g. “0C”, and compares it to a list.

I’m using Java 6 so can’t switch on a string and was initially planning on using switch on Enums but didn’t realise that Enums have to start with a letter.

Is there a simple way to achieve something like the following without a whole series of “if, else if…” statements?:

public void code(String oc) {

switch (oc) {
    case 00:
        // do something
        break;
    case 0A:
        // do something else
        break;
    case A1:
                   ....
             }

Thanks,
Robert.

Answer 1

In Java 6, it is not possible to do this directly. You have to convert the String values to numbers (somehow), and then switch on the numbers. For instance:

switch (Integer.parseInt(oc, 16)) {
case 0x00:
    // do something
    break;
case 0x0A:
    // do something else
    break;
case 0xA1:
    ....
}

The string to number conversion is relatively expensive, and probably negates the performance benefit of using a switch … unless you have a large number of distinct cases.