javascript或jquery：鼠标事件

Question

Need your help in understanding this code..Is this Javascript ( expression language ) or JQuery. I tried to understand but didn't get it.

var interval = 0, changed = false;
...............
...............

var start = function () {
    $(document).on('mousedown mousemove scroll touchstart touchmove keydown', change);
    setInterval(check, 1000);
};

 var change = function () {
    changed = true;
};

var check = function () {
   console.log("changed .....");
};

start();

Basically I want to do something ( business logic ) if user had performed some events on browser.Got this code on net and felt like something this is doing the same what i want.

Answer 1

It's both. jQuery is a Javascript library.

Answer 2

var start = function () {
    $(document).on('mousedown mousemove scroll touchstart touchmove keydown', change);
    setInterval(check, 1000);
};

$(document) refers to your entire HTML document. ON will attach an event handler function for one or more events to the selected elements. In your example , it'll attach the mousedown mousemove scroll touchstart touchmove keydown events to the document . Once any of those events occur , the change method gets called.

setInterval is used to call a method repeatedly for the given duration.In your Example , it calls the check method every 1000ms or 1 second

Answer 3

This following part is jQuery specific, all other are pure JavaScript.

$(document).on('mousedown mousemove scroll touchstart touchmove keydown', change);

This is a event handler of jQuery which is calling a native javascript function change() .

Notes:

• To run the jQuery part you need to import jQuery Library from their site.

• You can identify the jQuery selectors by user of $ infront. ( $ does not always means jQuery)