How Validation is used in JavaScript
In this article I have described about required field validator used in JavaScript
JavaScript Validation
JavaScript is helpful to validate data/information given by user before give to the server.
Mainly following are the points which typically are checked by a JavaScript
- Required fields empty or not
- A valid e-mail address
- A valid date
- Value in a numeric field
Required field Validator
The following function checks weather user has left required field
function notEmpty()
{
var myTextField = document.getElementById('myText');
if(myTextField.value != "")
alert("Thank you ! You have entered: " + myTextField.value)
else
alert("You didn't enter anytext ! please enter some text?")
}
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Lets take an example as
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Required field validator MCN Solution</title>
<script type="text/javascript">
function notEmpty(){
var myTextField = document.getElementById('myText');
if(myTextField.value != "")
alert("Thank you ! You have entered: " + myTextField.value)
else
alert("You didn't enter anytext ! please enter some text?")
}
</script>
<input type='text' id='myText' />
<input type='button' onclick='notEmpty()' value='VALIDATE' />
</head>
<body>
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Output
When run it and left blank TextBox then
when we enter some text in TextBox
Further Readings
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