NSArray *keys = @[@"duration"];

Question

Created Aug ’15

Replies 2

Boosts 0

Participants 2

I never saw such a terminology until now. I have a vague idea about this - but that's not enough. Who can translate this line of code into classical Objective-C code?

Thanks for helping

gefa

Boost

Answer 1

Ken Thomases OP

Aug ’15

Accepted Answer

@[ … ] is an Objective-C array literal. It is similar to [NSArray arrayWithObjects:…, nil]. One difference is that +arrayWithObjects: considers the first nil it finds as the terminator. So, if you have variables in the list, like [NSArray arrayWithObjects:var1, var2, var3, nil] and var2 happens to be nil, your list will only be 1 element long. It will contain var1 and that's it.

By contrast, @[ … ] throws an exception if any of the elements in the list are nil. So, @[ var1, var2, var3 ] will throw an exception is var2 is nil. This is better.

Of course, the array literal syntax is also a lot nicer.

1

Answer 2

gefa OP

Aug ’15

Thanks for your prompt reply.

Does there exist something like a dictionary where one can lookup 'synonyms' resp. 'new terminology' like these ones?

Unfortunately, Apple's manuals and guides often use the newest terminology without referring to older ones.

Best regards

gefa

0