Regular Expressions

RegularExpressions.swift

var email = "mehmetfarhan@gmail.com"
var pattern = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"

// Using NSPredicate
var predicate = NSPredicate(format: "SELF MATCHES %@", pattern)

// Using range
var range = email.range(of: pattern, options: .regularExpression)

// Using NSRegularExpression
func checkIsValid(_ string: String, pattern: String) -> Bool {
    let regex = try! NSRegularExpression(pattern: pattern, options: .dotMatchesLineSeparators)
    let result = regex.firstMatch(
        in: string,
        options: NSRegularExpression.MatchingOptions(rawValue: .zero),
        range: NSMakeRange(.zero, string.count)
    )
    guard result != nil else { return false }
    return true
}

range != nil // true
predicate.evaluate(with: email) // true
checkIsValid(email, pattern: pattern) // true

print("\(email) is Valid Email ? \(range != nil)") // mehmetfarhan@gmail.com is Valid Email ? true
print("\(email) is Valid Email ? \(predicate.evaluate(with: email))") // mehmetfarhan@gmail.com is Valid Email ? true
print("\(email) is Valid Email ? \(checkIsValid(email, pattern: pattern))") // mehmetfarhan@gmail.com is Valid Email ? true