CODEWITHSUNDEEP
iosobjective-cif-statementenumsswitch-statement
Duy Khanh Nguyen
Duy Khanh Nguyen

Reputation: 55

Using Enum and Switch on Objective-C

I have a view with 3 text fields:

  1. Current password
  2. New password
  3. Confirm new password

The requirement is, to check the validity of these passwords, if the conditions are not satisfied, there will be a alert view popup.

  1. If user inputs the wrong current password
  2. New password must have more than 8 letters
  3. the new passwords must match

I used if-else but it seems not to be suitable, and tried switch-case instead. But it still doesn't work.

My code:

NSString *textFromBox1 = [stringArray objectAtIndex:0];
NSString *textFromBox2 = [stringArray objectAtIndex:1];
NSString *textFromBox3 = [stringArray objectAtIndex:2];

enum ErrorCase{
    oldPasswordCase,
    newPasswordLength,
    newPasswordCheck,
};

enum ErrorCase error;

if ([textFromBox1 length] < 2) {
    error = oldPasswordCase;
} else if ([textFromBox2 length] < 8) {
    error = newPasswordLength;
} else if (textFromBox2 != textFromBox3) {
    error = newPasswordCheck;
}

switch (error) {
    case oldPasswordCase:
    {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"過ち"
                                                        message:@"現在のパスワードが間違っています。"
                                                       delegate:self
                                              cancelButtonTitle:@"OK"
                                              otherButtonTitles:nil];
        [alert show];
    }
        break;
    case newPasswordLength:
    {
        UIAlertView *alert2 = [[UIAlertView alloc] initWithTitle:@"過ち"
                                                         message:@"パスワードを8文字以上で入力してください。"
                                                        delegate:self
                                               cancelButtonTitle:@"OK"
                                               otherButtonTitles:nil];
        [alert2 show];

    }
        break;
    case newPasswordCheck:
    {
        UIAlertView *alert3 = [[UIAlertView alloc] initWithTitle:@"過ち"
                                                         message:@"新しいパスワードとパスワード（確認）が間違っています。"
                                                        delegate:self
                                               cancelButtonTitle:@"OK"
                                               otherButtonTitles:nil];
        [alert3 show];
    }
        break;

    default:
        break;
}

}

Upvotes: 0

Views: 1209

Answers (3)

vadian
vadian

Reputation: 285200

In Objective-C the argument in a switch statement must be an integer.

Use the NS_ENUM macro to declare the enum as integer

typedef NS_ENUM (NSInteger, ErrorCase) {
    oldPasswordCase,
    newPasswordLength,
    newPasswordCheck,
};

Then declare the error variable

ErrorCase error;

And as mentioned in Mateusz's answer you have to use isEqualToString to compare two strings.

Edit: Your if - else chain is not exhaustive which could cause unexpected behavior. Either add a default none case and assign it to error or make sure that the if - else chain considers all cases (thanks to Idali for the hint).

Upvotes: 2

Tony
Tony

Reputation: 542

I think you can do like this without enum:

NSString *textFromBox1 = [stringArray objectAtIndex:0];
NSString *textFromBox2 = [stringArray objectAtIndex:1];
NSString *textFromBox3 = [stringArray objectAtIndex:2];
NSString *alertString = nil;
if ([textFromBox1 length] < 2) {
    alertString = @"現在のパスワードが間違っています。";
} else if ([textFromBox2 length] < 8) {
    alertString = @"パスワードを8文字以上で入力してください。";
} else if (![textFromBox2 isEqualToString:textFromBox3]) {
    alertString = @"新しいパスワードとパスワード（確認）が間違っています。";
}

if (alertString) {
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"過ち"
                                                    message:alertString
                                                   delegate:self
                                          cancelButtonTitle:@"OK"
                                          otherButtonTitles:nil];
    [alert show];
}

Upvotes: 0

Mateusz
Mateusz

Reputation: 1224

this code is checking if two pointers are the same not two strings:

if (textFromBox2 != textFromBox3)

to compare strings you should use:

[textFromBox2 isEqualToString: textFromBox3]

Upvotes: 1

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