How do I pop up an alert in JavaScript?
Matthew Martinez 
How do I pop up an alert in JavaScript?
I tried alert"HELLO" but that didn't work.
Can someone tell me the correct syntax?
18 Answers
You need to add parentheses:
alert("HELLO");Unlike VBScript, JavaScript requires parentheses around function calls.
Therefore, you need to write alert("Hello!");
It's also preferable (but not required) to end every statement with a semicolon ;.
Finally, if you aren't already, you need to put it in a script block, like this:
<script type="text/javascript"> alert("Hello!");
</script>You can put JavaScript inside a script tag in an HTML page, or you can make a standalone .js file and double-click on it (in Windows) to run it using WSH.
<script type="text/javascript" > alert("hello");
</script>if you're having problems with alerts, it probably means your javascript is disabled in your browser, but if it isn't these methods should solve your issue.
<script type="text/javascript" > window.alert("Hello World!"); alert("Hello World!");
</script>Just add parantheses
alert("Hello");<script type="text/javascript">alert("Hello");</script>There are a few ways.
Use your web browser, type this code in address bar.
javascript:alert("Hello World!")Open web developer in your web browser, go to console and type:
alert("Hello World!")Type the code in .html or .js code as shown in other answers above.
<html>
<head>
<script type="text/javascript"> function myFunction(){ alert("hello"); }
</script> </head>
<body>
<input type="submit" onClick="myFunction()">
</body>
</html>Here is the JavaScript function which has an alert box. This function is called by clicking on the submit button.
