Question

I hope this will make sense:
I need to create a foreach function in javascript that will be used like this:

foreach(["A", "B", "C"], function(letter, done) {
    // do something async with 'letter'
    doSomthing(letter, done); // ***
}, function () {
    // final callback that is called after all array has been visted.
    // do some final work
});

So I was thinking about the following implementation:

var foreach = function(array, func, ready) {
    if (!array.length)
        ready();
    var that = this;
    func(array[0], function(){
        that.foreach(array.slice(1, array.length), func, ready);
    });
}

And it seems that it actually works! very cool.

But I was thinking if there is a solution that doesn’t use recursion?
I couldn’t think of one…

Answer 1

Your approach is technically correct but it is not good to do in such a way.
Pls implement using promise pattern in javasript .
I recommend you using when.js an open source js available on git for implementing promise pattern Pls refert to the below code

   var service = {
            fetch: function (query) {

                // return a promise from the function
                return when(["A", "B", "C"].forEach(function (name) {
                    alert(name);
                }));
            }
        };

        service.fetch("hello world").then(function () {
            alert("work has been completed");
        });