Skip to main content

JavaScript Comments

JavaScript Comments

Comments can be added to explain the JavaScript, or to make the code more readable.
Single line comments start with //.
The following example uses single line comments to explain the code:

Example

<script type="text/javascript">
// Write a heading
document.write("<h1>This is a heading</h1>");
// Write two paragraphs:
document.write("<p>This is a paragraph.</p>");
document.write("<p>This is another paragraph.</p>");
</script>

JavaScript Multi-Line Comments

Multi line comments start with /* and end with */.
The following example uses a multi line comment to explain the code:<script type="text/javascript">
/*
The code below will write
one heading and two paragraphs
*/
document.write("<h1>This is a heading</h1>");
document.write("<p>This is a paragraph.</p>");
document.write("<p>This is another paragraph.</p>");
</script>

Using Comments to Prevent Execution

In the following example the comment is used to prevent the execution of a single code line (can be suitable for debugging):

Example

<script type="text/javascript">
//document.write("<h1>This is a heading</h1>");
document.write("<p>This is a paragraph.</p>");
document.write("<p>This is another paragraph.</p>");
</script> In the following example the comment is used to prevent the execution of a code block (can be suitable for debugging):

Example

<script type="text/javascript">
/*
document.write("<h1>This is a heading</h1>");
document.write("<p>This is a paragraph.</p>");
document.write("<p>This is another paragraph.</p>");
*/
</script>

Using Comments at the End of a Line

In the following example the comment is placed at the end of a code line:

Example

<script type="text/javascript">
document.write("Hello"); // Write "Hello"
document.write(" Dolly!"); // Write " Dolly!"
</script>

Comments

Post a Comment

Popular posts from this blog

Toshiba Canada enters all-in-one PC market

Toshiba of Canada has thrown its hat into the all-in-one personal computer (PC) ring with the launch this week of the Toshiba DX730, a 23” all-in-one machine designed for users who want a large display and multimedia features in an environment where space is at a premium. It's Toshiba's first foray into this form factor, said Mini Saluja, national training manager with Toshiba of Canada, building on its experience in the laptop market. The DX730 has a 23” full HD multitouch display with a glossy black finish on an aluminum stand. It comes with a matching Bluetooth keyboard and mouse, and boasts Onkyo stereo speakers with Waves MaxxAudio sound processing. Two models of the DX730 will initially be available. The $899 model features a second-generation Intel Core i3 processor with 4GB of DDR3 memory, a 1TB 7200 RPM hard drive, a DVD SuperMulti Drive and HDMI in. For $1,049, you can move up to a model with an NVIDIA Geforce GT 540M processor and Intel Core i5, as we...
1 comment
Read more

Xiaomi Mi 11 Ultra review

  Introduction Now that the Pro moniker has gone mainstream, it's Ultra that has come to represent the cream of the crop, and the Xiaomi Mi 11 Ultra can wear that badge proudly. Limited to its home market last year, the ultimate Mi has gone global this time around, and we're happy to have it for review today. We're torn whether it's the camera system's physical appearance that is more striking or the hardware inside. A simply massive raised area on the back looks bolted on, almost after the fact, it's hard to miss, and it's a great conversation starter even if it's not everyone's cup of tea. But its size is warranted - the main camera packs the largest sensor used on a modern-day smartphone, and next to it - two more modules unmatched in their own fields, in one way or another. Oh, and yes, there's also a display here - because why not, but also because it can be useful. There's a lot more than 1.1 inches of ...
Post a Comment
Read more

JavaScript Where To

JavaScript in <body> The example below writes the current date into an existing <p> element when the page loads: Example <html> <body><h1>My First Web Page</h1> <p id="demo"></p> <script type="text/javascript"> document.getElementById("demo").innerHTML=Date(); </script> </body> </html>
Post a Comment
Read more