Skip to main content

JavaScript Basic: Three Useful Built-In Methods To Act Your Site


In the last post, I shared five primitive data types. Even though I could write some basic variables and do some math in the console, I don't see any action from the website. 

How to let website take action?

We will need to know three built-in methods:

Alert

It pops up a message to the user, and it alerts the user.

Console.log

What console.log will do is print something to the JavaScript console.

Prompt

Prompt is very useful for us because it lets us get input from a user. The second part of prompt is that we can store it in a variable.

Now I am going to apply those three built-in methods in HTML, so you can see how they work.

Firstly, I create a simple HTML page, and I only add the title. Then I add a <script> tag and link to a separate file named "script.js".


I want my site to pop up a message when you open it. In the "script. js" file, I name my variable as "userName", and it equal to prompt("What is your name?"). 


It allows users to enter their name in the pop up window.  


Then I create an alert message which is alert ("Nice to meet you," + userName). 


Once I enter the name "Marry", the userName variable value will be stored. After I enter the name and click OK, the site pops up a new alert message "Nice to meet you, Marry".



For the console.log part, we can't see it on the site, but we can find it out by inspecting the site. It is located on the "console" place.




Comments

Popular posts from this blog

Intermediate Express.js: How To Add Styles & Partials in EJS File?

So far, we only have simple HTML tags and ejs tags in each ejs file. Every template page has no style at all. And the basic HTML header and footer are also missing. Today, I learned how to add styles and partials in ejs file. Link Style Step One: Touch a Separate CSS file I create a new directory "Style" under the "EJSDemo" directory, then I add a new CSS file "app.css" inside "Style" folder. Step Two: Add app.use(express.static()) in the app.js I add app.use(express.static("style")) in the "app.js". This will tell Express.js to serve the content of "Style" directory. Step Three: Write styles in CSS file I simple give body an orange background color and set text color to be grey. Step Four: Link to CSS file in the EJS file I just add <link> tag to link the "app.css" file on the top of the h1 tag in each ejs template. As the result, when I run the app and...

My Story: A Mommy Start To Learn Code From Zero

From Google Image I am not a programmer, and I thought I would never become one. Everytime I see someone is coding, I think he or she must be very talent.  For me, coding is a very difficult subject to learn. Not only the language has so many rules, but also the logical reasoning behind the language is complex.  In my graduated school, I knew many friends who didn't have any coding background, but they are doing programmer or developer jobs now. Some of them went to school to study coding, and some of them  learned to code by themselves. Their stories are so impressive.  I wasn't ready to learn code until I finished my first Chinese book "留学,我的青春呀!" recently. I always want to be a writer and write my own book. I started writing blog three years ago, and I updated my post two to three times every week. As I enjoyed writing , I started to get some followers, likes, and good comments on my blog. Then, I decided to plan my first book. My First...

Three Most Common HTML Form Elements You Should Know

When I visited the Facebook page at the first time, it required me to sign up. Therefore, I completed the sign up form to create my new account. The form is very simple to fill in because it only asks for very common information such as full name, phone number, new password, birthday, and gender. It only took me one or two minutes to finish the form. Not only Social media sites require us to sign up first before we post anything, but many business or eCommerce sites also ask us to create new account before we take any action. For example, when I go to the Origins skin care site, it will pop up a email sign up form window. To encourage new customers to sign up, it gives a 15% off for the first order. It is definitely an attractive call-to-action message. Anyway, if your website requires users to sign up, you need to know how to create a HTML form. Yesterday, I just learned how to build a simple HTML form from Udemy course. And it is not that hard. All you need to kno...