Advertisements
Advertisements
Question
Explain about the popup dialog boxes in JavaScript.
Solution
JavaScript supports three important types of dialog boxes. Dialog boxes are also called as Popup Boxes, These dialog boxes can be used to raise an alert, or to get confirmation on any input or to have a kind of input from the users. JavaScript supports three kind of popup boxes: Alert box, Confirm box, and Prompt box.
- Alert Dialog Box:
An alert dialog box is mostly used to give a warning message to the users. For example, if one input field requires entering some text but the user does not provide any input, then as a part of the validation, you can use an alert box to give a warning message. Alert box gives only one button “OK” to select and proceed.
The syntax of alert box is:
Alert(“Message”);
(or) Window.alert(“Message”);Example:
alert(“Name is compulsory entry”);
(or) window.alert(“Name is compulsory entry”);Alert Dialog Box Code:
<Html>
<Head>
<Title>Demo Program – To test Alert Dialog Box in JavaScript </Title>
</Head>
<Body>
<script ianguage=”javascript” type=”text/
javascript”>
var value1 = 522, value2=10;
window.alert(“Data1 : “+value1);
alert(“Data1 :”+value2);
</script>
</Body>
</Html>Output:
- Confirm Dialog Box:
A confirmation dialog box is mostly used to take user’s consent on any option. It displays a dialog box with two buttons: OK and Cancel. If the user dicks on the OK button, the confirm() will return true. If the user clicks on the Cancel button, then confirm() returns false.
The syntax of confirm dialog box is:
confirm(“message”);
(or)
window.confirm(“message”);Example:
confirm(“Hai Do you want to continue:”);
(or)
window.confirm(“Hai Do you want to continue:”);Confirm Dialog Box Code:
<Html>
<Head>
<Title>Demo Program - To test Confirm Dialog Box in JavaScript </Title>
</Head>
<Body>
<script language="javascript" type="text/javascript">
var value1 = 522, value2=10;
window.confirm("Data1 : "+value1);
confirm("Data2 :"+value2);
</script>
</Body>
</Html>Output:
- Prompt Dialog Box:
The prompt dialog box is very useful when the user want to pop-up a text box to get user input. Thus, it enables you to interact with the user. The user needs to fill in the text box field and then click OK.
The prompt dialog box is displayed using a method called prompt() which takes two parameters:
- a label which you want to display in the text box and
- a default string to display in the text box.
This dialog box has two buttons: OK and Cancel. If the user clicks the OK button, the prompt() will return the entered value from the text box. If the user clicks the Cancel button, the prompt() returns null.
Th e Syntax of prompt dialog box is,
Prompt(“Message”,”defaultValue”);
(or)
window.promptC’sometext””defaultText”);Example:
prompt (“Enter Your Name:”,”Name”);
(or)
window.prompt (“Enter Your Name:”,”Name”);Prompt Dialog Box Code:
<Html>
<Head>
<Title>Demo Program - To test Prompt Dialog Box in JavaScript </Title>
</Head>
<Body>
<script language="javascript" type="text/javascript">
var sname = prompt("Please enter your name", "Name");
</script>
</Body>
</Html>Output:
