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:
