Question

I have this array (below) and I’m trying to check if it has specific values.

var a = [ true, "lipsum" ];

What I need to do, is to check if a[0] is true and if a[1] is “lipsum”

I could check both values separately:

a[0] === true && a[1] === 'lipsum' // true

…to shorten the code a bit, I tried to do this:

a === [ true, 'lipsum'] // false

Why is this code example above false and is there another way to achieve what I’m trying to do?

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I could do this:

a.join() === 'true,lipsum' // true

though I can’t help but feel that there is a better way..?

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• jsfiddle

Answer 1

Each array is a separate object, so the equality operator cannot be used to compare them. Assuming that you have a strict comparison of known arguments to do, the first method you use is the best.

If you have another array of arguments that the original array must contain, you must use a loop, although you could abstract it:

Array.prototype.contains = function (array) {
    for (var x = 0; x < array.length; x++) {
        if (this.length < x || this[x] !== array[x]) {
            return false;
        }
    }
    return true;
}

http://jsfiddle.net/q5DvG/1/