Web Technology - Old Questions
6. How can you define event handler? Write a JavaScript to demonstrate event handling.
5 marks
|
Asked in 2074
Event handlers are JavaScript code that are not added inside the <script> tags, but rather, inside the html tags, that execute JavaScript when something happens, such as pressing a button, moving your mouse over a link, submitting a form etc. The basic syntax of these event handlers is:
name_of_handler="JavaScript code here"
For example:
<a href="http://google.com" onClick="alert('hello!')">Google</a>
When the above link is clicked, the user will first see an alert message before being taken to Google.
Some event handlers used in JavaScript:
JavaScript code to demonstrate event handling:
<html>
<head>
<script type = "text/javascript">
function sayHello() {
alert("Hello World")
}
</script>
</head>
<body>
<p>Click the following button and see result</p>
<form>
<input type = "button" onclick = "sayHello()" value = "Say Hello" />
</form>
</body>
</html>