JavaScript seems to be everywhere these days. Until now, I only used it when the need arose while doing front end web development, but recently, I wanted to learn the language more properly. So the next question that popped into my mind was which IDE or editor has the JavaScript auto complete / IntelliSense and debugging capabilities? I was already familiar with the Visual Studio, so I wondered, if I can just use that for this purpose. It turns out you can and this is the topic of this article.
First half of the article will show, how to create a front-end JavaScript HTML web project in Visual Studio and in the second half, we will add HTML and JavaScript code to create a simple web application.
Step 1 – Create a new Web Site
I first tried to find a template for JavaScript Project in Visual Studio, but I didn’t find any. So I created an Empty Web Site project instead.
The steps are as follows:
- In Visual Studio, go to File > New > Web Site
- A window named "New Web Site" will open. On the left side, select Templates > Visual C# or Visual Basic, and then choose “ASP.NET Empty Web Site” Template from the list of templates.
Click image to enlarge
- At the bottom of the same window we choose "Web location" for our project. We can choose between File System, HTTP, FTP). I used a File System.
- Choose the location of the project and Click OK.
A new project will be created. In solution Explorer, you will notice the project will be empty except for a single file named web.config. This file is a configuration file for ASP.NET web application. We won't use ASP.NET here, but we still need web.config file to have debugging enabled.
In the next step, we will create a HTML, CSS and a JavaScript file.
Step 2 – Adding new items to the project
First we will add a new HTML page.
- Right-click on project in Solution Explorer
- A context menu will appear. Select Add > Add New Item as shown below:
Click image to enlarge
- An "Add New Item" window will open with different items to choose from.
Click image to enlarge
- Select "HTML Page" and give it a name
index.html. - Click on Add.
The created HTML file will contain basic HTML elements.
Now let's add a CSS file. We will add a few styles in it to make the page look better. Repeat the steps as before, but at step 4, select "Style sheet" and let's name it style.css and Click OK. The created file will contain a <body> selector with no declaration.
All that is left is to add a new JavaScript file. Again repeat the steps 1 to 3 and for step 4, select a "JavaScript File" instead. Give it a name hello.js and click on Add. The created JavaScript file will be empty.
And this is how you can create a JavaScript project using Visual Studio.
And now a few words about Debugging.
Debugging JavaScript with Visual Studio
I thought the debugging of JavaScript in Visual Studio would be straightforward. Unfortunately, debugging only works when you run the project in Internet Explorer browser. It doesn’t seem to work with any other browser. While learning plain JavaScript, this should not be an issue, but when you start to add libraries and frameworks, it might become a problem.
Step 3 - Creating a simple Web JavaScript Project
In the rest of the article, we will create a simple web page that uses JavaScript for its functionality. It is as basic as it can be, but it might be a useful starting point for those not that familiar with JavaScript. We will create a web page, where the user enters their name into the input field and after submitting, the page will greet you using the submitted name as shown below:
So let's begin adding the necessary code to the files we created.
Adding code to the HTML file
Open HTML file index.html and add this code inside the <body> tag:
<form> What is your name: <input type="text" size="20" id="myname" /> <button type="button" id="mybutton">Submit</button> </form> <div id="hellomessage"></div>
Quick code explanation
Let’s examine the above code more closely by focusing on yellow highlighted lines 2, 3 and 5:
-
Line 2:
What is your name: <input type="text" size="20" id="myname" />
Here we have an HTML input text element. The id attribute of the element is used inside
hello.jsfile. -
Line 3:
<button type="button" id="mybutton">Submit</button>
We have a button. The id attribute will also be used in the JavaScript file.
-
Line 5:
<div id="hellomessage"></div>
Here we have an empty <div> element that is used as a placeholder. Code inside the
hello.jsfile will append the resulting message inside this <div>.
Include JavaScript file inside HTML page
There is one more step before we finish with our HTML file. We need to reference our created hello.js javascript file inside the index.html. This will cause the JavaScript file to load, when the index.html runs. We achieve this by adding the following line before the ending </body> tag.
<script src="hello.js"></script>
But Why there and not in the </head>? Because by placing it at the end of the <body> tag, we ensure that objects in HTML are loaded before any code in JavaScript file references them. For more information about where to include JavaScript files, check this article from 2008.
hello.js file from Solution Explorer into the opened index.html file.And we are done with index.html. Expand the code below, to see the entire content of the file:
<!DOCTYPE html>
<html>
<head>
<title></title>
<meta charset="utf-8" />
</head>
<body>
<form>
What is your name: <input type="text" size="20" id="myname" />
<button type="button" id="mybutton">Submit</button>
</form>
<div id="hellomessage"></div>
<script src="hello.js"></script>
</body>
</html>
Now let's turn our attention to the hello.js file.
Adding JavaScriptcode in hello.js file
If not already opened, open hello.js by double-clicking on the file in Solution Explorer and add the following code:
function ShowHelloMessage() {
var name = document.getElementById("myname");
document.getElementById("hellomessage").innerHTML = "Hello, " + name.value;
}
document.getElementById("mybutton").onclick = ShowHelloMessage;
Here, we created a function named ShowHelloMessage (lines 1-4) and that function is then referenced in line 5. Let's examine this in more detail.
-
Line 2:
var name = document.getElementById("myname");We use getElementById function that will return the element with the id=”myname”. In our case, this will be a textbox field from
index.html. We use this variable in the next line (name.value). -
Line 3:
document.getElementById("hellomessage").innerHTML = "Hello, " + name.value;Now we use the getElementById function, which returns an element with id=”hellomessage”. This is the id of the empty <div> element inside
index.html. We use a innerHTML property on this element to insert a "Hello, " text and also a value ofname.value, which contains a value of the textbox from the line 2. -
Line 5:
document.getElementById("mybutton").onclick = ShowHelloMessage;The getElementById returns the element with the id="mybutton", which in our case is the button. We pass our ShowHelloMessage function to button's onclick event handler, so that when the button is clicked, this function gets executed.
With the above code, the "hello message" is displayed only when button is clicked, but not when enter key is pressed. Let's fix that next.
Adding support for "enter" key
There are several ways to achieve this. Here is a quick solution that requires changes of HTML file in two places:
- Inside our
<input>field, we add onkeydown event that executes a code every time a user presses a key. The modified code for<input>would look like this:<input type="text" size="20" id="myname" onkeydown = "if (event.keyCode == 13) document.getElementById('mybutton').click()" />The code inside the onkeydown event checks if enter key has been pressed and if so, click() method is called on our button. The click() method is used to simulate a click event.
- Since we only have a single input field, the click event in previous step will simulate a "submit" click, which is not what we want. To prevent this from happening, we can simply add another input field and hide it, like so:
<input type="text" style="display: none;" />
And we are done. Now, if you simply press enter key after typing a name, it should have the same effect as if you clicked on a button.
Adding some CSS styles
Now let's style the page a little using CSS. We already added the style.css file into our project, we just need to reference that file inside index.html, so open the index.html and add the following code inside the <head> tag:
<link href="style.css" rel="stylesheet" />
You can also drag and drop the style.css file inside the opened index.html file and the above code will be created by Visual Studio automatically.
Now let's add some style rules. Inside the style.css, add the following:
body {
font-size:1em;
font-family:Arial;
background:#eee;
}
#hellomessage {
font-weight:bold;
}
The finished JavaScript application in action
And we are done. You can test the whole code below:
See the Pen Very Simple JavaScript innerHTML Example by HowToDevCode (@HowToDevCode) on CodePen.
Conclusion
If you want to learn JavaScript and you are looking the editor / IDE, that has auto completion / IntelliSense and debugger support, then Visual Studio might be the IDE of choice. We can easily create web projects that uses JavaScript by creating an empty web site and then simply add HTML and JavaScript files. The only drawback is the debugging, since it seems to only work when the project is run in IE browser.
Which IDE do you prefer? Drop a comment and let us know.
Evan
October 13, 2016Hi, I'm trying to improve my JavaScript skills, and this tutorial is very helpful. There's one part I don't quite understand though:
I've tried it without this code, and it doesn't work as I'd expect it to, so this code is obviously doing something; but what exactly it does is still unclear to me. Why don't we want the enter button to simulate a "submit" event? Isn't this exactly what clicking on the "submit" button would do? Why do the two mechanisms work differently without the above code?
Thanks a lot!
admin
October 13, 2016Hi,
I'm glad you have found this tutorial helpful.
The reason for avoiding submit behavior is that this would submit the form and then reload / refresh the page, which is not what we want. We don't want to send the form's data to the server. We want to process that data using JavaScript on the same page.
That is why
<button type="button" >was used. It doesn't have any default behavior, so we can use the events of that button to call client side JavaScript code. In our case, we usedonclickevent to call ShowHelloMessage function.Helgy
March 7, 2017You solved my problem with VS, thx.
Naman
November 21, 2017How did you add the .css file
I used property but not getting same results
admin
November 21, 2017Good catch. I didn't mention anything about CSS. I have now updated the article.
Moller
October 14, 2020In the section "Debugging JavaScript with Visual Studio" you mentioned that JavaScript debugging only works in IE. Do you know if this has been fixed in the new VS 2019 version to use Google Chrome or MS Edge ? Thank you.
admin
October 14, 2020Hi,
I just tested it on Visual Studio 2019 and the debugging of JavaScript works on both Google Chrome and Edge, while it's not working on Firefox for some reason.