How javascript works in html
IntroductionJavaScript, also abbreviated to JS, is a programming language used in web development. As one of the core technologies of the web alongside HTML and CSS, JavaScript is used to make webpages interactive and to build web apps. Modern web browsers, which adhere to common display standards, support JavaScript through built-in engines without the need for additional plugins. Show When working with files for the web, JavaScript needs to be loaded and run alongside HTML markup. This can be done either inline within an HTML document or in a separate file that the browser will download alongside the HTML document. This tutorial will go over how to incorporate JavaScript into your web files, both inline into an HTML document and as a separate file. Adding JavaScript into an HTML DocumentYou can add JavaScript code in an HTML document by employing the dedicated HTML tag The Generally, JavaScript code can go inside of the document However, if your script needs to run at a certain point within a page’s layout — like when using Let’s consider the following blank HTML document with a browser title of index.html
Right now, this file only contains HTML markup. Let’s say we would like to add the following JavaScript code to the document:
This will enable the webpage to display an alert with the current date regardless of when the user loads the site. In order to achieve this, we will add a
To begin with, we’ll add the JavaScript code between the index.html
Once you load the page, you will receive an alert similar to this: If we were modifying what is shown in the body of the HTML, we would need to implement that after the index.html
The output for the above HTML document loaded through a web browser would look similar to the following: Scripts that are small or that run only on one page can work fine within an HTML file, but for larger scripts or scripts that will be used on many pages, it is not a very effective solution because including it can become unwieldy or difficult to read and understand. In the next section, we’ll go over how to handle a separate JavaScript file in your HTML document. Working with a Separate JavaScript FileIn order to accommodate larger scripts or scripts that will be used across several pages, JavaScript code generally lives in one or more The benefits of using a separate JavaScript file include:
To demonstrate how to connect a JavaScript document to an HTML document, let’s create a small web project. It will consist of
We can start with our previous HTML template from the section above: index.html
Now,
let’s move our JavaScript code that will show the date as an script.js
We can add a reference to this script to the
The Let’s consider this line in the context of our HTML file, in this case, within the index.html
Finally, let’s also edit the
style.css
We can reference that CSS file within the index.html
Now, with the JavaScript and CSS in place we can load the Now that we’ve placed the JavaScript in a file, we can call it in the same way from additional web pages and update them all in a single location ConclusionThis tutorial went over how to incorporate JavaScript into your web files, both inline into an HTML document and as a separate From here, you can learn how to work with the JavaScript Developer Console and how to write comments in JavaScript. How is JavaScript used in HTML?JavaScript enables dynamic interactivity on websites when it is applied to an HTML document. JavaScript helps the users to build modern web applications to interact directly without reloading the page every time. JavaScript is commonly used to dynamically modify HTML and CSS to update a user interface by the DOM API.
How does HTML and JavaScript work together?HTML provides the basic structure of sites, which is enhanced and modified by other technologies like CSS and JavaScript. CSS is used to control presentation, formatting, and layout. JavaScript is used to control the behavior of different elements.
How does JavaScript works on a website?The way JavaScript works is interesting. Inside a normal Web page you place some JavaScript code (See How Web Pages Work for details on Web pages). When the browser loads the page, the browser has a built-in interpreter that reads the JavaScript code it finds in the page and runs it.
How does JavaScript code work?Whenever we run a JavaScript program inside a web browser, JavaScript code is received by the browser's engine and the engine runs the source code to obtain the output. In a standard JavaScript engine, the source code goes through several steps and gets executed as you can see in the above given diagram.
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