JavaScript Output

JavaScript Display Possibilities

JavaScript can "display" data in different ways:

• Writing into an HTML element, using innerHTML or innerText.
• Writing into the HTML output using document.write().
• Writing into an alert box, using window.alert().
• Writing into the browser console, using console.log().

Using innerHTML

To access an HTML element, you can use the document.getElementById(id) method.

Use the id attribute to identify the HTML element.

Then use the innerHTML property to change the HTML content of the HTML element:

Example

# My First Web Page

My First Paragraph

 document.getElementById("demo").innerHTML = "

## Hello World

";

Using innerText

To access an HTML element, use the document.getElementById(id) method.

Then use the innerText property to change the inner text of the HTML element:

Example

# My First Web Page

My First Paragraph

 document.getElementById("demo").innerText = "Hello World";

Using document.write()

For testing purposes, it is convenient to use document.write():

Example

# My First Web Page

My first paragraph.

document.write(5 + 6);

Example

# My First Web Page

My first paragraph.

 Try it

Using window.alert()

You can use an alert box to display data:

Example

# My First Web Page

My first paragraph.

window.alert(5 + 6);

You can skip the window keyword.

In JavaScript, the window object is the global scope object. This means that variables, properties, and methods by default belong to the window object. This also means that specifying the window keyword is optional:

Example

# My First Web Page

My first paragraph.

alert(5 + 6);

Using console.log()

For debugging purposes, you can call the console.log() method in the browser to display data.

Example

console.log(5 + 6);

JavaScript Print

JavaScript does not have any print object or print methods.

You cannot access output devices from JavaScript.

The only exception is that you can call the window.print() method in the browser to print the content of the current window.

Example

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Video: JavaScript Output