Given an array and predicate, find the first matching element

Question

Is there an existing function that finds the first array element that matches some general predicate?

$.fn.findFirstMatching = function(predicate) {
    var result;
    $.each(this, function(index, value) {
        if (predicate(index, value)) {
            result = {index: index, value: value};
        }
    });
    if (result) {
        return result;
    }
};

Answer 1

As of ES2015, you can use Array.prototype.find

An example of using it looks like this:

// outputs the first odd number
console.log([2,4,10,5,7,20].find(x => x%2))

Answer 2

Another solution would be:

$.grep(yourArray, function (value, index) { return value == 42 } )[0]

Note that the order of the arguments should be value, index

Docs for jQuery.grep.

Of course, using _underscore is much more elegant and efficient (as $.grep applies the predicate on the all items of the array, it doesn't stop after the first match), but anyway :)