Share 12 practical jQuery code snippets_jquery

jQuery is an excellent JavaScript library that is very famous among WEB developers and web designers. It helps web designers develop many creative and beautiful WEB pages.

This article mainly shares 12 useful jQuery skills, the specific content is as follows

Here are some tips I’ve collected that will help you improve the creativity and functionality of your website layouts and applications.

1. Open the link in a new window

Using this code, when you click on a hypertext link, it will open in a new window, giving users a better experience:

$(document).ready(function() {
 //select all anchor tags that have http in the href
 //and apply the target=_blank
 $("a[href^='http']").attr('target','_blank');
});
 

2. Set timer

$(document).ready(function() {
 window.setTimeout(function() {
 // some code
 }, 500);
});

3. Set equal height columns

Use the following code to make each column in your web application have the same height:

<div class="equalHeight" style="border:1px solid">
 <p>First Line</p>
 <p>Second Line</p>
 <p>Third Line</p>
</div>
<div class="equalHeight" style="border:1px solid">
 <p>Column Two</p>
</div>
<script src="http://apps.bdimg.com/libs/jquery/1.11.1/jquery.min.js"></script>
<script>
$(document).ready(function() {
 equalHeight('.equalHeight');
});
//global variable, this will store the highest height value
var maxHeight = 0;
function equalHeight(col) {
 //Get all the element with class = col
 col = $(col);
 //Loop all the col
 col.each(function() {
 //Store the highest value
 if ($(this).height() > maxHeight) {
 maxHeight = $(this).height();
 }
 });
 //Set the height
 col.height(maxHeight);
}
</script>

4. jQuery preloaded images

This trick can speed up the loading of images on web pages:

jQuery.preloadImagesInWebPage = function() {
 for (var ctr = 0; ctr & lt; arguments.length; ctr++) {
 jQuery("").attr("src", arguments[ctr]);
 }
}
// 使用方法：
$.preloadImages("image1.gif", "image2.gif", "image3.gif");
// 检查图片是否被加载
$('#imageObject').attr('src', 'image1.gif').load(function() {
 alert('The image has been loaded…');
});

5. Position the element in the middle of the page

<div id="foo" style="width:200px;height: 200px;background: #ccc;"></div>
<script src="http://apps.bdimg.com/libs/jquery/1.11.1/jquery.min.js"></script>
<script type="text/javascript">
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:
$('#foo').center();
</script>
 

6. Disable the right mouse button

$(document).ready(function() {
 //catch the right-click context menu
 $(document).bind("contextmenu", function(e) {
 //warning prompt - optional
 alert("No right-clicking!");
 //delete the default context menu
 return false;
 });
});

7. Calculate the number of sub-elements

<div id="foo">
 <div id="bar"></div>
 <div id="baz">
 <div id="biz"></div>
 <span><span></span></span>
 </div>
</div>
<script src="http://apps.bdimg.com/libs/jquery/1.11.1/jquery.min.js"></script>
<script type="text/javascript">
 //jQuery code to count child elements $("#foo > div").size()
alert($("#foo > div").size())
</script>

8. Change style list

This code will help you change the style list.

 $(document).ready(function() {
 $("a.cssSwap").click(function() { 
 //swap the link rel attribute with the value in the rel 
 $('link[rel=stylesheet]').attr('href' , $(this).attr('rel')); 
 }); 
 });

9. Use jQuery to set text size

By adding this code, users can reset the text size (increase or decrease) according to their needs.

 $(document).ready(function() {
 //find the current font size
 var originalFontSize = $('html').css('font-size');

//Increase the text size
 $(".increaseFont").click(function() {
 var currentFontSize = $('html').css('font-size');
 var currentFontSizeNumber = parseFloat(currentFontSize, 10);

var newFontSize = currentFontSizeNumber*1.2;
 $('html').css('font-size', newFontSize);
 return false;
 });

//Decrease the Text Size
 $(".decreaseFont").click(function() {
 var currentFontSize = $('html').css('font-size');
 var currentFontSizeNum = parseFloat(currentFontSize, 10);

var newFontSize = currentFontSizeNum*0.8;
 $('html').css('font-size', newFontSize);
 return false;
 });

// Reset Font Size
 $(".resetFont").click(function(){
 $('html').css('font-size', originalFontSize);
 });
 });

10. Detect current mouse coordinates

Using this JS code, you can get mouse coordinates in any browser.

 $(document).ready(function() {
 $().mousemove(function(e)
 {
 $('# MouseCoordinates ').html("X Axis Position = " + e.pageX + " and Y Axis Position = " + e.pageY);
 });

11. Get the X/Y axis 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);
 });

12. Return to top link

This code is very practical for relatively long pages. Users do not need to pull the scroll bar to return to the top, but can directly click "Return to Top".

 $(document).ready(function() {
 //when the id="top" link is clicked
 $('#top').click(function() {
 //scoll the page back to the top
 $(document).scrollTo(0,500);
 }
 });

jQuery is one of the best libraries for JavaScript, supporting Ajax and HTML script clients. It is mainly used for event processing and animation production. In addition, jQuery also has various plug-ins that allow developers to create web pages in the fastest time.

I hope this article will be helpful to everyone learning jquery programming.