Question

我是客观C的新手，我被困在我的身上。我搜索了一些问题，但似乎没有人回答我的具体需求，希望你们能提供帮助！：）

我正在制作一个包含两个组件的选择器视图;一个与所有美国和一个与他们的首都。

现在当按下按钮时，我想要一个'if else语句'来检查两个数组的索引是否匹配，以及它是否确实创建了一个动作。有人可以帮我解决开放状况吗？现在它给了我'预期表达'错误。

if (_stateList objectAtIndex:[]== _capitalList objectAtIndex[]) {

    // Defining State & capitalnames by row
    NSInteger stateRow = [self.picker selectedRowInComponent:StatesList];
    NSInteger capitalRow = [self.picker selectedRowInComponent:CapitalsList];

    // Defining the Selected states and selected capital in the row
    NSString *selectedState = self.stateList[stateRow];
    NSString *selectedCapital = self.capitalList[capitalRow];

    // Giving a title to the alert message
    NSString *title = [[NSString alloc] initWithFormat:@"You selected %@ and %@", selectedState, selectedCapital];

    // Alert Message
    UIAlertController *alert = [UIAlertController alertControllerWithTitle:title message:@"Thats right, +1 for you!" preferredStyle:UIAlertControllerStyleAlert];

    UIAlertAction *action = [UIAlertAction actionWithTitle:@"Great!" style:UIAlertActionStyleDefault handler:nil];

    [alert addAction:action];
    [self presentViewController:alert animated:YES completion:nil];

    // Updating the scores
    _rightScore++;
    _rightAnswer.text = [NSString stringWithFormat:@"%i", _rightScore];
    _scoreTotal = _rightScore - _wrongScore;
    _scoreLabel.text = [NSString stringWithFormat:@"Score: %i", _scoreTotal];


} else {

    // Defining State & capitalnames by row
    NSInteger stateRow = [self.picker selectedRowInComponent:StatesList];
    NSInteger capitalRow = [self.picker selectedRowInComponent:CapitalsList];

    // Defining the Selected states and selected capital in the row
    NSString *selectedState = self.stateList[stateRow];
    NSString *selectedCapital = self.capitalList[capitalRow];

    // Giving a title to the alert message
    NSString *title = [[NSString alloc] initWithFormat:@"You have selected %@ and %@", selectedState, selectedCapital];

    // Alert Message
    UIAlertController *alert = [UIAlertController alertControllerWithTitle:title message:@"Thats not correct, -1 for you." preferredStyle:UIAlertControllerStyleAlert];

    UIAlertAction *action = [UIAlertAction actionWithTitle:@"Let me try again!" style:UIAlertActionStyleDefault handler:nil];

    [alert addAction:action];
    [self presentViewController:alert animated:YES completion:nil];

    // Updating the scores
    _wrongScore++;
    _wrongAnswer.text = [NSString stringWithFormat:@"%i", _wrongScore];
    _scoreTotal = _rightScore - _wrongScore;
    _scoreLabel.text = [NSString stringWithFormat:@"Score: %i", _scoreTotal];


}

Answer 1

您要将所选行分配给两个变量stateRow和capitalRow。你似乎想要做的是比较这两个变量，看看它是否具有相同的值，例如if (stateRow == capitalRow) { ... } else { ... }

HTH

比较对象索引

1 个答案: