Question

129

rated 0 times [ 133] [ 4] / answers: 1 / hits: 16029 / 13 Years ago, wed, june 22, 2011, 12:00:00

I'm doing some trouble-shooting and want to add a check that a parameter to a function is a number. How do I do this?

Something like this...

function fn(id) {

    return // true iff id is a number else false

}

Even better is if I can check that the parameter is a number AND a valid integer.

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Member since Sun, Feb 27, 2022

2 Years ago

answered 13 Years ago theron · Accepted Answer

function fn(id) {

    return typeof(id) === 'number';

}

To also check if it’s an integer:

function fn(id) {

    return typeof(id) === 'number' &&

            isFinite(id) &&

            Math.round(id) === id;

}