NSString *emailRegex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}"; NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegex]; BOOL matched = [predicate evaluateWithObject: email]; if(!matched) { [self simpleAlert: @"正しいメールアドレスを入力ください"]; return; }