Given an email id and the task is to validate the email id is valid or not. The validation of email is done with the help of Regular Expressions.
Approach 1:
- RegExp – It checks for the valid characters in the Email-Id (like, numbers, alphabets, few special characters.)
- It is allowing every special symbol in the email-id (like, !, #, $, %, ^, &, *) symbols in the Email-Id but not allowing the second @ symbol in ID.
Example: This example implements the above approach.
<!DOCTYPE html> <html>
<head>
<title>
How to validate email address
using RegExp in JavaScript ?
</title>
</head>
<body style = "text-align:center;">
<h1 style = "color:green;">
GeeksForGeeks
</h1>
<p id = "GFG_UP" style =
"font-size: 15px; font-weight: bold;">
</p>
<button onclick = "GFG_Fun()">
click here
</button>
<p id = "GFG_DOWN" style =
"font-size: 24px; font-weight: bold; color: green;">
</p>
<script>
var up = document.getElementById('GFG_UP');
var down = document.getElementById('GFG_DOWN');
var email = 'GeeksForGeeks@gmail.com';
up.innerHTML = "Click on the button to check the "
+ "validity of Email Id.<br>" + email;
function isEmail(email) {
// Regular Expression (Not accepts second @ symbol
// before the @gmail.com and accepts everything else)
var regexp = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
// Converting the email to lowercase
return regexp.test(String(email).toLowerCase());
}
function GFG_Fun() {
down.innerHTML = isEmail(email);
}
</script>
</body>
</html>
|
Output:
-
Before clicking on the button:
-
After clicking on the button:
Approach 2:
- RegExp – It checks for the pattern like anything@anything.anything
- Not like the previous example, RegExp is accepting every character along with special character multiple times.
Example 2: This example implements the above approach.
<!DOCTYPE HTML> <html>
<head>
<title>
How to validate email address
using RegExp in JavaScript ?
</title>
</head>
<body style = "text-align:center;">
<h1 style = "color:green;">
GeeksForGeeks
</h1>
<p id = "GFG_UP" style =
"font-size: 15px; font-weight: bold;">
</p>
<button onclick = "GFG_Fun()">
click here
</button>
<p id = "GFG_DOWN" style =
"font-size: 24px; font-weight: bold; color: green;">
</p>
<script>
var up = document.getElementById('GFG_UP');
var down = document.getElementById('GFG_DOWN');
var email = 'Gee%E^%ksForGeeks@gmail.com';
up.innerHTML = "Click on the button to check the "
+ "validity of Email Id.<br>" + email;
function isEmail(email) {
// Regular Expression (Accepts every special
// character along with @ symbol)
var regexp = /\S+@\S+\.\S+/;
// Converting the email to lowercase
return regexp.test(String(email).toLowerCase());
}
function GFG_Fun() {
down.innerHTML = isEmail(email);
}
</script>
</body>
</html>
|
Output:
-
Before clicking on the button:
-
After clicking on the button:
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