Question

The sample code mentioned below is a part of jQuery Countdown plugin by Keith Wood. Can some explain this

_attachCountdown: function(target, options) {
        var $target = $(target);
        if ($target.hasClass(this.markerClassName)) {
            return;
        }
        $target.addClass(this.markerClassName);
        var inst = {options: $.extend({}, options),
            _periods: [0, 0, 0, 0, 0, 0, 0]};
        $.data(target, PROP_NAME, inst);
        this._changeCountdown(target);
    }

Is there a reason specifically defining $target or its just same as our simple variables like var target.

Thanks in advance.

Answer 1

It is a simple variable, $ is just added to indicate to the code reader that a jQuery collection is stored inside. Javascript is quite “lenient” with variable names, the $ has no special meaning (opposed to PHP where it is needed before every variable name).

This method (var $target=$(target);) is used to save the result of $(target) (the jQuery collection itself, storing target) into a variable, so the jQuery collection does not need to be created everytime it is needed.