SO-33461584

by David Thomas

JavaScript

// naming the function, defining the
// arguments to pass:
function commonElements(arr1, arr2) {

    // iterating over arr1, using
    // Array.prototype.some() wherein
    // 'el' is the current element of
    // the array over which we're iterating:
    return arr1.some(function (el) {

        // finding the 'el' value in
        // arr2; and comparing the index
        // if the 'el' value isn't found
        // in arr2 it returns -1:
        return arr2.indexOf(el) > -1;
    });
}

var one = [1, 2, 3, 4, 5],
    two = [5, 6, 7, 8, 9];

console.log(commonElements(one, two)); // true