Can JavaScript function execution be interrupted?

Question

Having an object to store data.

var store = {
    elements: [],
    eventsEnabled: true,
    addElement: function(element) {
        this.elements.push(eleme         


        

Answer 1

Would it not be more sensible to pass the eventsEnabled in as a parameter to the addElement method?

var store = {
    elements: [],
    addElement: function(element,eventsEnabled) {
        this.elements.push(element);
        if (eventsEnabled) {
            // Code that triggers event, calls handlers... whatever
        }
    }
};

First:

setInterval(function() {
    store.addElement('hello',false);
}, 12000);

Second:

setInterval(function() {
    store.addElement('bye',true);
}, 12000);

Answer 2

Further to @Jamiec's suggestion, you could also look at passing the event function in as well:

var store = {
    elements: [],
    addElement: function(element, callback) {
        this.elements.push(element);
        if (callback !== undefined) {
            callback();
            // Common code that triggers event, calls handlers... whatever
            alert("I'm Common Event Code");
        }
    }
};​

Used as such:

setInterval(function() {
    store.addElement('hello', function(){ alert("I'm Special Event Code!"); });
}, 12000);

Thus, if an event is needed, you can pass it in, else just leave it out.

Answer 3

JavaScript is single-threaded. A function cannot be interrupted, so you can be sure each function block will complete before another begins.

(However, if a function makes an asynchronous call, other functions may execute before the asynchronous operation starts. That doesn't happen in your code, though, that I can see, besides the setTimeout calls, and you can be sure those will execute in the correct order.)