Question

您好我尝试使用一些用户输入的字符串，如果字符串有引号（不知道单/双）怎么办？

具体来说，我想在字符串中存储一些R代码，例如

 _webViewController = [[WebViewController alloc] init];
    _webViewController.delegate = self;
    _animationController = [[AnimationController alloc] initWithPresentedViewController:_webViewController
                                                                                      presentingView:presentingView];
    _webViewController.transitioningDelegate = _animationController;

    [self handleGesture:_hostViewController
         presentingView:presentingView
presentedViewController:_webViewController];


- (void)handleGesture:(UIViewController *)presentingViewController
       presentingView:(UIView<PresentingViewType>*)presentingView
presentedViewController:(UIViewController *)presentedViewController{
    UIPanGestureRecognizer *panGesture = presentingView.panGesture;
    CGPoint viewTranslation = [presentingView.panGesture translationInView:presentingView];
    CGFloat progress = fabs(viewTranslation.y / 200);
    switch (panGesture.state) {
        case UIGestureRecognizerStateBegan:
            _isInteracting = YES;
            _transitionController = [UIPercentDrivenInteractiveTransition new];
            [presentingViewController presentViewController:presentedViewController
                                                   animated:YES
                                                 completion:nil];
        case UIGestureRecognizerStateChanged:
            _shouldCompleteTransition = progress > 0.5;
            [_transitionController updateInteractiveTransition:progress];
        case UIGestureRecognizerStateEnded:
            _isInteracting = NO;
            if (_shouldCompleteTransition) {
                [_transitionController finishInteractiveTransition];
            } else {
                [_transitionController cancelInteractiveTransition];
            }
            _transitionController = nil;
        case UIGestureRecognizerStateFailed:
        case UIGestureRecognizerStatePossible:
        case UIGestureRecognizerStateCancelled:
            break;

    }

}

如何将此代码存储在字符串中（稍后我将使用x = 'a' y = "b"执行它）

更新

如果要求用户在eval(parse(text=x))提示符下输入字符串，R会自动修复引号：

readline()

我正在考虑如何允许用户粘贴多行

Answer 1

你必须要转义引号

x = '\'a\''
y = "\"b\""

或者将字符串存储在您要存储的引号的替代中

x = "'a'"
y = '"b"'

Answer 2

我想你说的是： -

null

如何使用引号处理字符串

2 个答案: