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Discussion on: If (all) else is complicated, switch to switch?

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Replies for: Little OT here. I think switches are great for revealing unexpected program flows in a multi branch szenario, which is why the exact match conditio...

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Andrew Bridge •

I agree with your initial point, but not necessarily that switches are the answer.

In your example, I'd probably do something like:

const states = {
    foo: stateA,
    bar: stateB
};

const f = (value) => {
    if (!(value in states)) {
        throw new Error(`No state for ${value}`);
    }
    return states[value]();
}
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...or more generically assuming things weren't as 1-to-1...

const f = (value) => {
    if (value === 'foo') {
        return stateA();
    }
    if (value === 'bar') {
        return stateB();
    }
    throw new Error(`No state for ${value}`);
}
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The second is probably the easiest to understand out of all of them (including the switch imo) so I'd probably lean towards that, but in every case, undefined behaviours are caught appropriately.