JavaScript Examples: validate email using regex

function validateEmail(email) {

// Define the regular expression for validating an email

// The regex pattern explained:

// ^ asserts position at start of the string

// [a-zA-Z0-9._%+-]+ matches one or more of the allowed characters before the @

// @ matches the literal @ symbol

// [a-zA-Z0-9.-]+ matches one or more of the allowed characters for the domain part

// . matches the literal dot symbol

// [a-zA-Z]{2,} matches two or more alphabetic characters for the top-level domain

// $ asserts position at the end of the string

const emailRegex = /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+.[a-zA-Z]{2,}$/;

// Test the email against the regex pattern

const isValid = emailRegex.test(email);

// Log the regex pattern used for validation

console.log("Regex Pattern: ", emailRegex);

// Log the email being tested and whether it is valid

console.log("Testing Email: ", email);

console.log("Is Valid: ", isValid);

return isValid;

}

const testEmails = [

"test@example.com", // Valid email

"user.name@domain.co", // Valid email

"invalid-email@", // Invalid email (missing domain part)

"@example.com", // Invalid email (missing local part)

"user@domain@domain.com", // Invalid email (multiple @ symbols)

"user@domain.c", // Invalid email (top-level domain too short)