HTML DOM Window alert() Method
HTML Window alert() method is used to display an alert box. It displays a specified message along with an OK button and is generally used to make sure that the information comes through the user. It returns a string that represents the text to display in the alert box.Â
Note: Alert boxes grab your attention and make you read a message and Using too many alerts stops you from doing other things on the webpage until you close them.
Syntax:
alert(message);
Parameter:
Message: It is the message that is needed to show in the alert box and it’s optional.
Example: Display an alert box by double-clicking a button.Â
html
<!DOCTYPE html>
< html lang = "en" >
< head >
< meta charset = "UTF-8" >
< meta name = "viewport"
content = "width=device-width, initial-scale=1.0" >
< title >Document</ title >
</ head >
< body >
< h1 style = "color: green;" >
GeeksforGeeks
</ h1 >
< p >
For displaying the alert message, double
click the "Show Alert Message" button:
</ p >
< button ondblclick = "myalert()" >
Show Alert Message
</ button >
< script >
function myalert() {
alert("Welcome to GeeksforGeeks.\n " +
"It is the best portal for computer" +
"science enthusiasts!");
}
</ script >
</ body >
</ html >
|
Output:
Example: Alert the hostname of the current URL
HTML
<!DOCTYPE html>
< html lang = "en" >
< head >
< meta charset = "UTF-8" >
< meta name = "viewport"
content = "width=device-width, initial-scale=1.0" >
< title >Alert Hostname Example</ title >
</ head >
< body style = "text-align: center;" >
< h1 style = "color: green;" >
Geeks
</ h1 >
< p >
To see the hostname of the current URL,
click the "Show Hostname" button:
</ p >
< button onclick = "showHostname()" >
Show Hostname
</ button >
< script >
function showHostname() {
let currentURL = window.location.hostname;
alert("The hostname of the current URL is: " + currentURL);
}
</ script >
</ body >
</ html >
|
Output:
Supported Browsers:
- Google Chrome 1
- Edge 12
- Firefox 1
- Opera 3
- Safari 1
We have a Cheat Sheet on Javascript where we covered all the important topics of Javascript to check those please go through Javascript Cheat Sheet-A Basic guide to JavaScript.
Last Updated :
16 Jan, 2024
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