NSPredicate(format:"SELF MATCHES %@", emailReg) おおNSPredicate式だfunc isValidEmailFormat2(string: String) -> Bool { let emailReg = "[a-zA-Z0-9._%+-/:~$^()&!']+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}" // valid regexp let regexp = try! NSRegularExpression.init(pattern: emailReg, options: []) let nsString = string as NSString let matchRet = regexp.firstMatch(in: string, options: [], range: NSRange.init(location: 0, length: nsString.length)) return matchRet != nil } isValidEmailFormat2(string: "aaa@aaa.com") isValidEmailFormat2(string: "aaa＠aaa.com")