Validate Email in JavaScript

Here are the various methods to validate email in JavaScript

1. Simple Validation with Regular Expression

function valid(email) {
    const pattern = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
    return pattern.test(email);
}
const email = "[email protected]";
console.log(valid(email) ? "Valid email address" : "Invalid email address");

Valid email address

In this example

• The valid function checks whether a given email address matches the standard email format using a regular expression.
• The pattern ^[^\s@]+@[^\s@]+\.[^\s@]+$ ensures the email has a valid structure: it starts with characters other than spaces or "@" ([^\s@]+), followed by an "@" symbol, a domain name, and a valid top-level domain.

2. Using Library validator.js

For robust email validation, we can use npm libraries like validator.js. before using it, first install it using npm.

npm install validator

const valid = require("validator");
const emailToValidate = "[email protected]";
console.log(valid.isEmail(emailToValidate)
    ? "Valid email address"
    : "Invalid email address");

Output

Valid email address

In this example

• The validator library's isEmail function is used to check whether the given email address is valid.
• The isEmail method evaluates "[email protected]" and returns true if it matches the standard email format.

3. Validate Multiple Emails

const emails = [
    "[email protected]",
    "invalid-email.com",
    "[email protected]"
];
emails.forEach(email => {
    console.log(`${email} is ${validator.isEmail(email) ? 'valid' : 'invalid'}.`);
});

In this example

• An array of email addresses is iterated using forEach, where each email is checked using the validator.isEmail function.
• The function determines whether each email matches the standard format and logs the result in the format: "email is valid" or "email is invalid".

4. Built-in HTML5 Validation

function valid(email) {
    const input = document.createElement('input');
    input.type = 'email';
    input.value = email;
    return input.checkValidity();
}
console.log(valid("[email protected]") ? "Valid email" : "Invalid email");

In this example

• The valid function checks if the provided email is valid using an <input> element with type "email".
• The console.log statement logs "Valid email" or "Invalid email" based on the result.