The HTML5 and tags make it simple to add media to a website. You need to set src attribute to identify the media source and include a controls attribute so the user can play and pause the media.The HTML5 video tag can have a number of attributes to control the look and feel and various functionalities of the control:sr. No.Attribute & Description1AutoplayThis boolean attribute if specified, the video will automatically begin to play back as soon as it can do so without stopping to finish loading the data.2AutobufferThis boolean attribute if specified, the video will automatically begin buffering ... Read More

Use Modernizr in HTML to detect a feature like audio through JavaScript:if (Modernizr.audio) {    /* properties for browsers that    support audio */ } else{    /* properties for browsers that    does not support audio */ }

Modernizr is a small JavaScript Library that detects the availability of native implementations for next-generation web technologies.Here is the list of features that can be detected by Modernizr −FeatureCSS PropertyJavaScript Check@font-face.fontfaceModernizr.fontfaceCanvas.canvasModernizr.canvasCanvas Text.canvastextModernizr.canvastextHTML5 Audio.audioModernizr.audioHTML5 Audio formatsNAModernizr.audio[format]HTML5 Video.videoModernizr.videoHTML5 Video FormatsNAModernizr.video[format]rgba().rgbaModernizr.rgbahsla().hslaModernizr.hslaborder-image.borderimageModernizr.borderimageborder-radiusbox-shadow.borderradiusModernizr.borderradiusbox-shadow.boxshadowModernizr.boxshadowMultiple backgrounds.multiplebgsModernizr.multiplebgsOpacity.opacityModernizr.opacityCSS Animations.cssanimationsModernizr.cssanimationsCSS Columns.csscolumnsModernizr.csscolumnsCSS Gradients.cssgradientsModernizr.cssgradientsCSS Reflections.cssreflectionsModernizr.cssreflectionsCSS 2D Transforms.csstransformsModernizr.csstransformsCSS 3D Transforms.csstransforms3dModernizr.csstransforms3dCSS Transitions.csstransitionsModernizr.csstransitionsGeolocation API.geolocationModernizr.geolocationInput TypesNAModernizr.inputtypes[type]Input AttributesNAModernizr.input[attribute]localStorage.localstorageModernizr.localstorageessionStorage.sessionstorageModernizr.sessionstorageWeb Workers.webworkersModernizr.webworkersapplicationCache.applicationcacheModernizr.applicationcacheSVG.svgModernizr.svgSVG Clip Paths.svgclippathsModernizr.svgclippathsSMIL.smilModernizr.smilWeb SQL Database.websqldatabaseModernizr.websqldatabaseIndexedDB.indexeddbModernizr.indexeddbWeb Sockets.websocketsModernizr.websocketsHashchange Event.hashchangeModernizr.hashchangeHistory Management.historymanagementModernizr.historymanagementDrag and Drop.draganddropModernizr.draganddropCross-window Messaging.crosswindowmessagingModernizr.crosswindowmessagingaddTest() Plugin APINAModernizr.addTest(str, fn)Read More

You can try to run the following code to detect a web worker feature available in a web browser:           Big for loop                      function myFunction(){             if (Modernizr.webworkers) {                alert("Congratulations!! You have web workers support." );             } else{                alert("Sorry!! You do not have web workers support." );             }          }                     Click me     The following is the result:

Here is an example of an error handling function in a Web Worker JavaScript file that logs errors to the console.ExampleWith error handling code, above example would become like the following:           Big for loop                var worker = new Worker('bigLoop.js');          worker.onmessage = function (event) {             alert("Completed " + event.data + "iterations" );          };          worker.onerror = function (event) {             console.log(event.message, event);          };          function sayHello(){             alert("Hello sir...." );          }                        

JavaScript was designed to run in a single-threaded environment, meaning multiple scripts cannot run at the same time. Consider a situation where you need to handle UI events, query and process large amounts of API data, and manipulate the DOM.JavaScript will hang your browser in situation where CPU utilization is high. Let us take a simple example where Javascript goes through a big loop:           Big for loop                function bigLoop(){             for (var i = 0; i

dragenterThe dragenter event is used to determine whether the drop target is to accept the drop. If the drop is to be accepted, then this event has to be canceled.dragoverThe dragover event, which is used to determine what feedback is to be shown to the user. If the event is canceled, then the feedback (typically the cursor) is updated based on the dropEffect attribute's value.

To resize the image before submitting the form, you need to use the drawImage() method.Scale the original image and draws the scaled version on the canvas at [0,0]context.drawImage( img, 0,0,img.width,img.height, 0,0,myWidth,UseHeight );Above, we saw the following:Here,var myWidth = Math.floor( img.width * Scale ); var myHeight = Math.floor( img.height * Scale );And,var x = Math.floor( ( world.width - myWidth) / 2 ); var y = Math.floor( ( world.height - myHeight) / 2 );

The DataTransfer object holds data about the drag and drop operation. This data can be retrieved and set in terms of various attributes associated with the DataTransfer object.The following are the attributes:Sr.No.DataTransfer attributes and their description1dataTransfer.dropEffect [ = value ]Returns the kind of operation that is currently selected.This attribute can be set, to change the selected operation.The possible values are none, copy, link, and move.2dataTransfer.effectAllowed [ = value ]Returns the kinds of operations that are to be allowed.This attribute can be set, to change the allowed operations.The possible values are none, copy, copyLink, copyMove, link, linkMove, move, all and uninitialized.3dataTransfer.typesReturns a DOMStringList ... Read More

To accept a drop, the drop target has to listen to at least three events. The dragenter event, which is used to determine whether the drop target is to accept the drop. If the drop is to be accepted, then this event has to be canceled. The dragover event, which is used to determine what feedback is to be shown to the user. If the event is canceled, then the feedback (typically the cursor) is updated based on the dropEffect attribute's value. Finally, the drop event, which allows the actual drop to be performed.