regularExpression.swift

let email: String = "beepeach@test.com"
let regularExpression: String = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,}"

if let _ = email.range(of: regularExpression) {
    print("Vaild Email Pattern")
} else {
    print("InVaild Email Pattern")                  // InVaild Email Pattern
}

if let _ = email.range(of: regularExpression, options: .regularExpression) {
    print("Vaild Email Pattern")                    // Vaild Email Pattern
} else {
    print("InVaild Email Pattern")
}


let fakeEmail: String = "beepeach@test.com "

if let _ = fakeEmail.range(of: regularExpression, options: .regularExpression) {
    print("Vaild Email Pattern")                     // Vaild Email Pattern
} else {
    print("InVaild Email Pattern")
}

if let range = fakeEmail.range(of: regularExpression, options: .regularExpression),
   range.lowerBound == fakeEmail.startIndex && range.upperBound == fakeEmail.endIndex {
    print("Vaild Email Pattern")
} else {
    print("InVaild Email Pattern")                   // InVaild Email Pattern
}