Trying to cast the return of objectAtIndex.
(MyClass *)[myArray objectAtIndex:1].name;
Can you cast inline like this in Objective-C?
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2 Answers
Yes you can:
((MyClass *)[myArray objectAtIndex:1]).name
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You can avoid casting altogether by replacing the dot-syntax of accessing properties with the regular method invocation syntax:
[[myArray objectAtIndex:1] name]
answered Jun 20, 2012 at 21:37
Sergey Kalinichenko
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7 Comments
Duncan C
That will throw a warning though, and if you compile with ARC I think it may change to an error.
graver
Yes this is a bad idea even if you are okay with the warning, if you remove the property
name from MyClass you will continue to get a warning, but your app will crash and the code is hard to maintain this way...
Sergey Kalinichenko
@graver There's never a warning when you use this syntax: it's either an error, or a warning-free compile. When the identifier
name does not correspond to a selector supported by any @interface in the system, an error is triggered. This approach works beautifully most of the time, and is a small price to pay for avoiding the need to provide an explicit cast.graver
@dasblinkenlight what you're saying is only valid when you're using ARC. I suppose you haven't developed apps prior ios5...
Sergey Kalinichenko
@graver Turning ARC off does not alter this behavior of the compiler: you do not get a warning when the identifier matches a selector of some object in the system, and you get an error when it does not match. I suppose there may be a bug in the compiler prior to LLVM that produces a warning, but that is not a good reason to avoid a perfectly valid syntax.
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