To place JavaScript in external file create an external JavaScript file with the extension .js. After creating, add it to the HTML file in the script tag. The src attribute is used to include that external JavaScript file.If you have more than one external JavaScript file, then add it to the same web page to increase the performance of the page.Let’s say the following new.js is our external JavaScript file −function display() {    alert("Hello World!"); }Now add the external JavaScript file to the HTML web page −                                      

To enhance performance, try to keep JavaScript external. The separate code makes it easier for web browsers to cache. However, use inline scripts only when you’re making single page websites. Still, it's better to use external code i.e. external JavaScript. To place JavaScript in external file create an external JavaScript file with the extension .js. After creating, add it to the HTML file in the script tag. The src attribute is used to include that external JavaScript file. If you have more than one external JavaScript file, then add it to the same web page to increase the performance of ... Read More

Anonymous FunctionsAnonymous, as the name suggests, allows creating a function without any names identifier. It can be used as an argument to other functions. This is how JavaScript anonymous functions can be used −var myfunc = function() {    alert(‘This is anonymous'); }Another example can be the following −setTimeout(function() {    alert('Demo'); }, 3000);Inline FunctionsAn inline function is a javascript function, which is assigned to a variable created at runtime. You can difference Inline Functions easily with Anonymous since an inline function is assigned to a variable and can be easily reused.This is how JavaScript inline functions can be used −var ... Read More

Create external JavaScript file with the extension .js. After creating, add it to the HTML file in the script tag. The src attribute is used to include that external JavaScript file.If you have more than one external JavaScript file, then add it in the same web page to increase performance of the page.Let’s say the following new.js is our external JavaScript file −function display() {    alert("Hello World!"); }Now add the external JavaScript file to the HTML web page −                                      

You can place the tags, containing your JavaScript, anywhere within your web page, but it is normally recommended that you should keep it within the tag or tag.It’s good for performance to add JavaScript in element. Here’s an example to add under … −                               Here’s an example to add under … −                                        

With JavaScript, you can put JavaScript anywhere on the page, whether inside or tag. But, it is a good practice to add JavaScript in the footer i.e. just before closing the tag. This is because −It loads script faster.It will not block any DOM content to load.It loads the web page before loading JavaScriptImproves display speedPage loads faster

To find whether the browser supports JavaScript or not, use the tag. The HTML tag is used to handle the browsers, which do recognize tag but do not support scripting. This tag is used to display an alternate text message.ExampleLive Demo           HTML noscript Tag                                                    Your browser does not support JavaScript!          

To redirect if JavaScript is not enabled in the web browser, add a script to the tag. Let us say you need to redirect to index.php if JavaScript is not enabled. ExampleHere’s how you can do this:           HTML noscript Tag                                                        html{display:none;}          

To find whether the browser supports JavaScript or nor, use the tag. The HTML tag is used to handle the browsers, which do recognize tag but do not support scripting. This tag is used to display an alternate text message.Here’s an example,           HTML noscript Tag                                              Your browser does not support JavaScript!          

To detect if JavaScript is disabled in a web browser, use the tag. The HTML tag is used to handle the browsers, which do recognize tag but do not support scripting. This tag is used to display an alternate text message.Here’s an example,           HTML noscript Tag                                                    Your browser does not support JavaScript!