How to check whether multiple values exist within an Javascript array

Question

So, I\'m using Jquery and have two arrays both with multiple values and I want to check whether all the values in the first array exist in the second.

Answer 1

You can use this simple function (renamed variables as per above answer for easy reading):

function contains(haystack, needles) {

    return needles.map(function (needle) { 
        return haystack.indexOf(needle);
    }).indexOf(-1) == -1;
}