定義驗證字符串時出錯

Question

我已經編寫了驗證美國郵政編碼的代碼......但它給了我錯誤，未知的轉義序列\ d在驗證字符串中。 代碼：

- (BOOL)zipcodevalidation:(NSString *)zipstring { 

    NSString *emailRegex = @"(^\d{5}(-\d{4})?$)"; 
    NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegex]; 

    return [emailTest evaluateWithObject:zipstring]; 
} 

Answer 1

你需要逃避反斜槓使該字符串不理解他們，像在字符串中使用類似\t轉義序列，\n等

@"(^\\d{5}(-\\d{4})?$)"; 

Answer 2

試試這個美國郵編valiadtion

- (BOOL)zipcodevalidation:(NSString *)zipstring { 

    NSString *emailRegex = @"(^[0-9]{5}(-[0-9]{4})?$)"; 


    NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegex]; 

    return [emailTest evaluateWithObject:zipstring]; 
}