How to restrict mail input in javascript

There are several ways to restrict mail input in JavaScript, depending on the specific requirements and constraints. Here are a few approaches:

Using a regular expression: You can use a regular expression to validate the input email address. For example:


const emailInput = document.getElementById('email');
const emailRegex = /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/;

emailInput.addEventListener('input', (e) => { const value = e.target.value; if (!emailRegex.test(value)) { // invalid email address, show error message or prevent submission } });

This regular expression matches most common email address formats, but may not cover all possible valid email addresses.

2. **Using a library or framework**: Many JavaScript libraries and frameworks, such as jQuery or React, provide built-in email validation functions. For example:
```javascript
const $emailInput = $('#email');
$emailInput.on('input', (e) => {
  const value = $emailInput.val();
  if (!$.validator.methods.email.test(value)) {
    // invalid email address, show error message or prevent submission
  }
});

Using a custom validation function: You can create a custom validation function that checks the input email address against a set of rules. For example:
```
const emailInput = document.getElementById('email');
```

function validateEmail(email) { const parts = email.split('@'); if (parts.length!== 2) return false; const localPart = parts[0]; const domain = parts[1]; if (!localPart ||!domain) return false; if (localPart.length > 64 || domain.length > 255) return false; // additional validation rules here return true; }

emailInput.addEventListener('input', (e) => { const value = e.target.value; if (!validateEmail(value)) { // invalid email address, show error message or prevent submission } });


4. **Using a third-party library**: There are many third-party libraries available that provide email validation functionality, such as EmailValidator.js or validate-email-address.js. You can include these libraries in your project and use their validation functions.

Remember to always validate user input on the server-side as well, as client-side validation can be easily bypassed by malicious users.

Mail Knowledge

How to restrict mail input in javascript