点符号vs方括号和在Objective-C中投射 [英] Dot notation vs square brackets and casting in Objective-C

问题描述

以下哪一个是Objective-C的最佳实践？

Which of the following is best practice in Objective-C?

UITableView* view = (UITableView*) [self view];
[view setSeparatorColor:[UIColor blackColor]];
[view release];

vs。

((UITableView*) self.view).separatorColor = [UIColor blackColor];

还是有更好的写法吗？ self.view 是一个 UIView * 。

Or is there a better way of writing this? self.view is a UIView*.

因为我有一个奇怪的样子（也许有一个更好的方式？）和因为下面的文本从官方文档，这暗示，这不仅仅是一个风格或个人喜好的问题：

I'm asking both because I have a weird looking cast (maybe there's a better way?) and because of the following text from the official documentation, which hints that it's more than just a matter of style or personal preference:

另一个优点是，当编译器检测到尝试写入只读的声明属性时，它可以发出错误信号。如果你使用方括号语法访问变量，编译器最多只能生成一个未声明的方法警告你调用了一个不存在的setter方法，并且代码在运行时失败。

A further advantage is that the compiler can signal an error when it detects an attempt to write to a read-only declared property. If you instead use square bracket syntax for accessing variables, the compiler—at best—generates only an undeclared method warning that you invoked a nonexistent setter method, and the code fails at runtime.

推荐答案

好吧...点符号最后编译成方括号，但它是由个人喜好。除非我设置/访问标量类型，否则我个人避免使用圆点符号。例如：...

Well.... dot notation compiles down to square brackets in the end, but it is down to personal preference. I personally avoid dot notation unless I am setting / accessing a scalar type, it is too easy to look at the following for instance...

view.step = 2.0;

...不知道step是标量属性还是setter方法等。更喜欢使用...

... and not know where step is a scalar property, or has a setter method etc. I prefer to be explicit and would use...

[view setStep:2.0];

但我再想想个人喜好。

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