20 Top jQuery Tips & Tricks for jQuery Programmers

jquery-tips-tricksFollowing are few very useful jQuery Tips and Tricks for all jQuery developers. I am sharing these as I think they will be very useful to you.
Disclaimer: I have not written all of the below code but have collected from various sources from Internet.

1. Optimize performance of complex selectors

Query a subset of the DOM when using complex selectors drastically improves performance:

var subset = $("");
$("input[value^='']", subset);

2. Set Context and improve the performance

On the core jQuery function, specify the context parameter when. Specifying the context parameter allows jQuery to start from a deeper branch in the DOM, rather than from the DOM root. Given a large enough DOM, specifying the context parameter should translate to performance gains.

$("input:radio", document.forms[0]);

3. Live Event Handlers

Set an event handler for any element that matches a selector, even if it gets added to the DOM after the initial page load:

$('button.someClass').live('click', someFunction);

This allows you to load content via ajax, or add them via javascript and have the event handlers get set up properly for those elements automatically.

Likewise, to stop the live event handling:

$('button.someClass').die('click', someFunction);

These live event handlers have a few limitations compared to regular events, but they work great for the majority of cases. Live event will work starting from jQuery 1.3

4. Checking the Index

jQuery has .index but it is a pain to use as you need the list of elements and pass in the element you want the index of

var index = e.g $('#ul>li').index( liDomObject );

The following is easier:

if you want to know the index of an element within a set, e.g. list items within a unordered list:

$("ul > li").click(function ()
{
    var index = $(this).prevAll().length;
});

5. Use jQuery data method

jQuery’s data() method is useful and not well known. It allows you to bind data to DOM elements without modifying the DOM.

6. Fadeout Slideup effect to remove an element

Combine more than one effects in jQuery to animate and remove an element from DOM.

$("#myButton").click(function() {
         $("#myDiv").fadeTo("slow", 0.01, function(){ //fade
             $(this).slideUp("slow", function() { //slide up
                 $(this).remove(); //then remove from the DOM
             });
         });
});

7. Checking if an element exists

Use following snippet to check whether an element exists or not.

if ($("#someDiv").length) {
    //hooray!!! it exists...
}

8. Add dynamically created elements into the DOM

Use following code snippet to create a DIV dynamically and add it into the DOM.
Further Reading: Dynamically Add/Remove rows in HTML table using JavaScript

var newDiv = $('<div></div>');
newDiv.attr("id","myNewDiv").appendTo("body");

9. Line breaks and chainability

Instead of doing:

$("a").hide().addClass().fadeIn().hide();

You can increase readability like so:

$("a")
  .hide()
  .addClass()
  .fadeIn()
  .hide();

10. Creating custom selectors

$.extend($.expr[':'], {
    over100pixels: function(a) {
        return $(a).height() > 100;
    }
});

$('.box:over100pixels').click(function() {
    alert('The element you clicked is over 100 pixels high');
});

11. Cloning an object in jQuery

Use .clone() method of jQuery to clone any DOM object in JavaScript.

// Clone the DIV
var cloned = $('#somediv').clone();

jQuery’s clone() method does not clone a JavaScript object. To clone JavaScript object, use following code.

// Shallow copy
var newObject = jQuery.extend({}, oldObject);

// Deep copy
var newObject = jQuery.extend(true, {}, oldObject);

12. Test if something is hidden using jQuery

We use .hide(), .show() methods in jquery to change the visibility of an element. Use following code to check the whether an element is visible or not.

if($(element).is(":visible") == "true") {
       //The element is Visible
}

13. Alternate way of Document Ready

//Instead of
$(document).ready(function() {
	//document ready
});
//Use
$(function(){
	//document ready
});

14. Selecting an element with . (period) in its ID

Use backslash in the selector to select the element having period in its ID.

$("#Address\\.Street").text("Enter this field");

15. Counting immediate child elements

If you want to count all the DIVs present in the element #foo

<div id="foo">
  <div id="bar"></div>
  <div id="baz">
    <div id="biz">
  </div>
  <span><span>
</div>

//jQuery code to count child elements
$("#foo > div").size()

16. Make an element to “FLASH”

jQuery.fn.flash = function( color, duration )
{
    var current = this.css( 'color' );
    this.animate( { color: 'rgb(' + color + ')' }, duration / 2 );
    this.animate( { color: current }, duration / 2 );
}
//Then use the above function as:
$( '#importantElement' ).flash( '255,0,0', 1000 );

17. Center an element on the Screen

jQuery.fn.center = function () {
    this.css("position","absolute");
    this.css("top", ( $(window).height() - this.height() ) / 2+$(window).scrollTop() + "px");
    this.css("left", ( $(window).width() - this.width() ) / 2+$(window).scrollLeft() + "px");
    return this;
}

//Use the above function as:
$(element).center();

18. Getting Parent DIV using closest

If you want to find the wrapping DIV element (regardless of the ID on that DIV) then you’ll want this jQuery selector:

$("#searchBox").closest("div");

19. Disable right-click contextual menu

There’s many Javascript snippets available to disable right-click contextual menu, but JQuery makes things a lot easier:

$(document).ready(function(){
    $(document).bind("contextmenu",function(e){
        return false;
    });
});

20. Get mouse cursor x and y axis

This script will display the x and y value – the coordinate of the mouse pointer.

$().mousemove(function(e){
	//display the x and y axis values inside the P element
    $('p').html("X Axis : " + e.pageX + " | Y Axis " + e.pageY);
});

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44 Comments

  1. Andrew says:

    Thanks for sharing these tips, very useful. I think readers would find this 5 jquery performance tips useful:

    http://jquery-howto.blogspot.com/2009/02/5-easy-tips-on-how-to-improve-code.html

  2. Dan Wellman says:

    Great list :D

    Couple of things though:

    number 7 – while that does work, you don’t need to check whether elements exist before selecting them. jQuery will not throw errors if you try to select elements not on the page (unlike most other libraries). Unnecessary checking of whether elements exist will slow things down a little.

    number 9 – this is in no way related to performance, in fact, it may even make scripts slower! Compression applications, such as YUI compressor, remove line-breaks from JS documents when you compress them. Line breaks do need to be processed and exist as characters, so unecessary line breaks are going to slow things down (even only by a few milliseconds)

    But some great tips apart from those :)

  3. Viral Patel says:

    @Andrew, Thanks for the comment and thanks for sharing the useful link.

    @Dan, Great insight and thanks for the comment :) Glad you liked the snippets. Feel free to go through rest of the articles of this site.

  4. heyyeah says:

    Great list, thanks. I’m may quesion #17, how to replicate being in top 20 but I’d just be quibbling :)

  5. Majnun says:

    @Dan: Regarding #9, you must admit that the virtually unnoticeable drop in speed is well worth the upgrade to readability

  6. Good list! thanks for sharing

  7. Viral Patel says:

    @Vipul, Thanks for the comment. Happy Reading :)

  8. Kyle Farris says:

    I’ve been using jQuery for about as long as it has existed (about 3-4 years) and I never knew there was “contextmenu” event. Never had to use it… but, it’s nice to know it exists.

  9. Acaz says:

    The item 13 is not good in performance.

  10. Nice collection of jQuery Tips and Tricks mate. I have also linked to yours from my blog post below where I am trying to collect the most useful and common jQuery code snippets for JavaScript over the web. Here is the title and the link to the jQuery link compilation endeavor:

    Ultimate collection of top jQuery tutorials, tips-tricks and techniques to improve performance

    http://technosiastic.wordpress.com/2009/09/24/collection-of-top-jquery-tutorials-tips-tricks-techniques-to-improve-performance/

  11. The tutor is very good …….

  12. مهپویا says:

    very powerful

  13. willy says:

    Thank you!happy reading…

  14. Arvind says:

    Nice tutorial.
    For more Jquery tutorials visit webspeaks.in

  15. Frank says:

    I tried #16 and it is not working. I found out that jQuery does not allow color property to be changed in .animate(). Any idea?

    • BadMonkey0001 says:

      You’ll need the jQuery UI code to animate non-numeric values now. You don’t need all the jQUI theme stuff, just the JS file.

  16. Raghunath says:

    Its very useful information..good one.

  17. papay says:

    Thanks for this list. especially for #17. Great tips!

  18. Nice tips and guides. Very useful.
    Thanks for the list.

  19. Kyathi says:

    Excellent art of knowledge. :-)

    • sanju dahiya says:

      yaa reaaaly nice

  20. Hosting Best says:

    Interesting alternative for the page loaded function, nice work!

  21. Thank you a lot for giving everyone an exceptionally nice possiblity to read articles and blog posts from here. It can be so nice and as well , full of a great time for me personally and my office co-workers to visit your website at minimum 3 times a week to find out the newest guides you have. And indeed, I’m also always impressed for the unbelievable techniques served by you. Some 3 ideas in this article are undeniably the simplest I have had.

  22. Keep working ,great job!

  23. Vijaya Anand says:

    Nice article. I also wrote a small article about this subject http://www.prideparrot.com/blog/archive/2011/9/interesting_things_from_jquery

  24. Mike says:

    I like #19 will defenatly use it

  25. dipak kumar burnwal says:

    great tips really helpful

  26. Virendra says:

    Great post.. But today i found something new about how to use selectors efficiently, which is really a great post indeed..

    Thought of sharing with your reader.
    http://jquerybyexample.blogspot.com/2011/11/tips-to-use-jquery-selectors.html

    Thanks,
    Virendra

  27. Mark says:

    I must admit it is a great list indeed. I am collecting jquery tips and tricks. I follow a jquery blog called jquerybyexample.blogspot.com. Recently this guy has also posted about top jquery tips and tricks. few are similar to yours but rest of them are really worth.

    http://jquerybyexample.blogspot.com/2011/12/best-jquery-tips-and-tricks.html

  28. Mark says:

    And yes forgot to mention that I have started following your blog as well…

  29. Its great that you collected most commnly used tricks of JQuery. I have been using few of them and this list really helped me. One of the common use is to make select the first drop down.

    $(“target option:first”).attr(‘selected’,’selected’);
    or
    $(“#target”).val($(“#target option:first”).val());

  30. Awesome tips specially 16 and17

  31. Rafael says:

    Really good and usefull collection. Thank you.

  32. Adam says:

    Great tips! Trying to get a grasp on jQuery and found that very useful.

  33. manikandan says:

    This is awesome. It will be very helpful for the beginners like me.
    Thank you very much for giving such as a wonderful article/

  34. Derrick says:

    #6 can be done like this – using delay().

    $(“#myButton”).click(function() {
    $(“#myDiv”).fadeTo(500, 0.01).delay(500).slideUp(500).delay(500).remove();
    });

  35. Timothy McClanahan says:

    Regarding #19, don’t ever do that. That’s actively user hostile. No no no.

  36. علیرضا says:

    Man you’re awesome! did you know about it? ;)
    very well-organized collection, thanks dude.

  37. XF says:

    in 15. with this method :

     

    you have $(“#foo > div”).size() = 1

  38. BadMonkey0001 says:

    $.fn.live() is dperecated. Please don’t use it.

  39. Maria says:

    This is a great jquery tutorials, thanks for sharing!

  40. Mercury says:

    Very helpful! I found 1 mistake though.

    Instead of:

    var newObject = jQuery.extend(true, {}, oldObject);

    you should use:

    var newObject;
    jQuery.extend(true, newObject, oldObject);

    Especially if you’re working with json data (I had a json list), it messes it up:
    This:

    data: [{property1:"value1",property2:value2}, { ... }]

    becomes this:

    ({0:{property1:"value1", property2:value2}, 1:{ ... }})
  41. Mahmoud Saeed says:

    Thanks you, it is a good tips,
    nice work

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