问题
Usually when we want to initialize NSMutableArray we use:
NSMutableArray *mArr = [[NSMutableArray alloc] initWithObjects: @"one", @"two", @"three", nil];
But, is it correct to use syntax like:
NSMutableArray *mArr = @[@"one", @"two", @"three"].mutableCopy;
I understand, that it will work a couple of nanoseconds longer. But I think the second way to be way more readable and I'm ready to sacrifice those nanoseconds.
Is it ok, to use this kind of construction? Does ARC clean that unused NSArray, that I'm using to get a mutable copy? Isn't it going to be a leak?
回答1:
But I think the second way to be way more readable
Personally, I find it more confusing, and even more confusing since you are using mutableCopy as if it was a property. Correct, correct, but totally misleading IMHO.
Why not just take advantage of inheritance?
NSMutableArray *ma = [NSMutableArray arrayWithObjects:@"foo", @"bar", nil];
Sometimes collections which are mutable by default would be of more use. * sigh *
回答2:
Yes, it's ok to initialize your mutable array that way, if you are willing (as you indicated) to pay the performance cost. ARC will clean everything up appropriately. It won't leak.
回答3:
I usually use arrayWithArray.
NSMutableArray *foo = [NSMutableArray arrayWithArray:@[@"one", @"two", @"three"]];
来源：https://stackoverflow.com/questions/19186756/is-it-correct-to-use-short-syntax-when-initializing-nsmutablearray