Question

I know that $(this) results in a jQuery object, but i often see (especieally in jQuery plugins) the use of return this.whatever what is the general rule?

Thanks

Answer 1

It depends on what this refers to.

Inside an event handler function this refers to the HTML element the event is raised from. To perform jQuery operations on the element, you use $(this) to wrap the HTML element.

this in the scope of a plugin method refers to the jQuery selection object itself. Additionally, in plugins the jQuery method each is used to perform a function to each element in a jQuery selection. This is often the way plugins are written to provide a new method:

jQuery.fn.alertClasses = function()
{
    // "this" refers to the jQuery object, returned by $(...)
    if(this[0] === undefined)
        return this;

    this.each(function() { 
        // "this" now refers to an HTML element in the jQuery object
        alert(this.className)
    });

    // "this" refers to the jQuery object again
    return this;
}

In short, it’s all about the context of the method. The jQuery documentation explains this concept whenever you’re looking at methods which change the value of this.