The innerHTML:
The innerHTML property can be used to modify your document's HTML on the fly.When you use
innerHTML, you can change the page's
content without refreshing the page. This can make your website feel
quicker and more responsive to user input.The
innerHTML property is used along with getElementById within your JavaScript code to refer to an HTML element and change its contents.The
innerHTML property is not actually part of the
official DOM specification. Despite this, it is supported in all major
browsers, and has had widespread use across the web for many years. DOM,
which stands for Document Object Model, is the hierarchy that you can
use to access and manipulate HTML objects from within your JavaScript.
The innerHTML Syntax
The syntax for using innerHTML goes like this:
document.getElementById('{ID of element}').innerHTML = '{content}';
{ID of element} is the ID of an HTML element and {content} is the new content to go into the element.
Basic innerHTML Example
Here's a basic example to demonstrate how innerHTML works. This code includes two functions and two buttons. Each function displays a different message and each button triggers a different function.
In the functions, the
getElementById refers to the HTML element by using its ID. We give the HTML element an ID of "myText" using id="myText". So in the first function for example, you can see that
document.getElementById('myText').innerHTML = 'Thanks!'; is setting the innerHTML of the "myText" element to "Thanks!".Code:
<script type="text/javascript">
function Msg1(){
document.getElementById('myText').innerHTML = 'Thanks!';
}
function Msg2(){
document.getElementById('myText').innerHTML = 'Try message 1 again...';
}
</script>
<input type="button" onclick="Msg1()" value="Show Message 1" />
<input type="button" onclick="Msg2()" value="Show Message 2" />
<p id="myText"></p>
Example 2: innerHTML With User Input
Here's an example of using innerHTML with a text field. Here, we display whatever the user has entered into the input field.Code:
<script type="text/javascript">
function showMsg(){
var userInput = document.getElementById('userInput').value;
document.getElementById('userMsg').innerHTML = userInput;
}
</script>
<input type="input" maxlength="40" id="userInput"
onkeyup="showMsg()" value="Enter text here..." />
<p id="userMsg"></p>
Example 3: Formatting with getElementById
In this example, we use the getElementById property to detect the color that the user has selected. We can then use style.color to apply the new color. In both cases, we refer to the HTML elements by their ID (using getElementById.)Code:
<script type="text/javascript">
function changeColor(){
var newColor = document.getElementById('colorPicker').value;
document.getElementById('colorMsg').style.color = newColor;
}
</script>
<p id="colorMsg">Choose a color...</p>
<select id="colorPicker" onchange="JavaScript:changeColor()">
<option value="#000000">Black</option>
<option value="#000099">Blue</option>
<option value="#990000">Red</option>
<option value="#009900">Green</option>
</select>
