Alert is a way of passing on some information to the page user/visitor OR simply it alerts the user about a certain event. Event like Page load, button click, form submit, clicked inside a field etc. See JavaScript Events for more.
The Alert command launches a PopUp box containing some text message for the visitor. The user is required to acknowledge the receipt of information usually by pressing a 'OK' button that appears in the box.
Syntax
Alert ("message");
Example
javascript alert box
In the example above, we put a Button on a simple web page. Besides we defined a function in the head section of the page, and named it js_alert. This function will launch the alert box whenever it is called.
We also programmed the button to call the function js_alert whenever the button is pressed(the button press event captured using Onclick event handler).
You can Copy Paste the code below into a new html file.
<html>
<head>
<title>JS PopUp Boxes</title>
<script type="text/javascript">
function js_alert()
{
alert("This is your first alert box");
}
</script>
</head>
<body>
<p>Clicking the Button below will launch an alert box.</p>
<input type="button" onclick="js_alert()" value="Launch Alert Box" />
</body>
</html>
Result
alert box in chrome
Note that the alert box appears as a separate small size window in Chrome browser.
The Alert command launches a PopUp box containing some text message for the visitor. The user is required to acknowledge the receipt of information usually by pressing a 'OK' button that appears in the box.
Syntax
Alert ("message");
Example
javascript alert box
In the example above, we put a Button on a simple web page. Besides we defined a function in the head section of the page, and named it js_alert. This function will launch the alert box whenever it is called.
We also programmed the button to call the function js_alert whenever the button is pressed(the button press event captured using Onclick event handler).
You can Copy Paste the code below into a new html file.
<html>
<head>
<title>JS PopUp Boxes</title>
<script type="text/javascript">
function js_alert()
{
alert("This is your first alert box");
}
</script>
</head>
<body>
<p>Clicking the Button below will launch an alert box.</p>
<input type="button" onclick="js_alert()" value="Launch Alert Box" />
</body>
</html>
Result
alert box in chrome
Note that the alert box appears as a separate small size window in Chrome browser.
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