Here I have one html form and one css file(style.css).”o-div” is the outer div and “i-div“is the inner div class.Example           center a div                              I am OUTER DIV                       I am INNER DIV,             I am in Center                     OutputI am OUTER DIV I am INNER DIV, I am in CenterStyle.cssbody {    background-color:Gray;    padding:30px; } .o-div {    padding:50px;    background-color:Lime; } .i-div {    background-color:Fuchsia;    max-width:400px;    height:200px;    margin: 0 auto;    text-align:center; }

To set the content of an iframe without src, use the jQuery html() method. You can try to run the following code to learn how to set the content of an iframe without src attribute −ExampleLive Demo      jQuery Selector                  $(document).ready(function() {     var context = $('iframe')[0].contentWindow.document;     var $body = $('body', context);     $body.html('Hello World!');   });        

To get the children of the $(this) selector, use the jQuery find() method. You can try to run the following code to get the children of the $(this) selector −ExampleLive Demo   jQuery Example       $(document).ready(function(){     $('#mydiv').click(function(){       alert($(this).find('img:last-child').attr('src'));    });   });   #my_div {    width: 200px;    height: 200px;    background-color: red;   }    

To center a div on the screen, use the jQuery centering function jQuery.fn.center. You can try to run the following code to learn how to center a div on the screen:ExampleLive Demo               $(document).ready(function(){       jQuery.fn.center = function(parent) {         if (parent) {           parent = this.parent();         } else {           parent = window;         }       this.css({        "position": "absolute",        "top": ((($(parent).height() ... Read More

You can use .is(‘:visible’) selects all elements that are visible.Example divvisible               $(document).ready(function () {          $("button").click(function () {             var dim = $('#div1').is(":visible");             if (dim == false) {                $('#div1').css({ "display": "block", "color": "red" });             }          });       });     Div is visible    Click Here

To count number of columns in a table with jQuery, use the each() function with attr(). You can try to run the following code to learn how to count column in a table:EaxmpleLive Demo       jQuery Example             $(document).ready(function(){       var num = 0;       $('tr:nth-child(1) td').each(function () {         if ($(this).attr('colspan')) {           num += +$(this).attr('colspan');         } else {         num++;       }     });    alert("Total Columns= "+num); });         -1st column-     -2nd column-     -3rd column-    

Example Live Demo table        table,th,td {       border:2px solid black;       margin-left:400px;    }    h2 {       margin-left:400px;    }    button {       margin-left:400px;    }            $(document).ready(function () {       $("button").click(function () {          var rowcount = $('table tr').length;          alert("No. Of Rows ::" +rowcount);       });    }); HTML TABLE NAME AGE DD 35 SB 35 AD 5 AA 5 Click Here

To check if table row exists or not, use the is() method, with the :visible selector −if($(".row").is(":visible")) {   alert("Visible!"); }You can try to run the following code to learn how to chck if a row exists or not. It even notifies when a new row is created −ExampleLive Demo   jQuery - Add Table Rows     table{    width: 100%;    margin: 25px 0;    border-collapse: collapse;   }   table, th, td{    border: 1px solid #6C220B;   }   table th, table td{    padding: 8px;    text-align: left;   }   ... Read More

To call a jQuery function after a certain delay, use the siteTimeout() method. Here, jQuery fadeOut() function is called after some seconds.You can try to run the following code to learn how to work with setTimeout() method in jQuery to call a jQuery function after a delay −ExampleLive Demo         $(document).ready(function(){     $("#button1").bind("click",function() {       setTimeout(function() {         $('#list').fadeOut();}, 2000);     });   });                    Voice        Speak      Write         The above content will fade out after 2 seconds

To make a jQuery function call after “X” seconds, use the siteTimeout() method.On button click, set the following and fade out the element. Here, we have also set the milliseconds. This is the delay that would occur before fading an element:$("#button1").bind("click",function() {    setTimeout(function() {       $('#list').fadeOut();}, 4000); });You can try to run the following code to learn how to work with setTimeout() method in jQuery:Example Live Demo               $(document).ready(function(){          $("#button1").bind("click",function() {             setTimeout(function() {                $('#list').fadeOut();}, 4000);             });          });               India       US       UK     The above data will fade out after 4 seconds