Objective-C syntax: Is ?: part of a ternary operator?

Question

I am looking through some Objective-C code and see the following line that doesn't' make sense:

dict ?: @{@"value":value}

What does the ?: mean in this context? I haven't been able to find anything about it anywhere, and it kind of looks like a ternary operator, but without the positive return value. Does this just mean return nothing if dict is non-nil, and the other dictionary if it is nil?

http://stackoverflow.com/questions/15911006/is-there-an-objective-c-equivalent-to-ifnull — vcsjones, Aug 04 '14 at 17:08
Or this one: http://stackoverflow.com/questions/3319075/ternary-conditional-operator-behaviour-when-leaving-one-expression-empty — Martin R, Aug 04 '14 at 17:10
I did search ?: Objective-C but it didn't come up with those, thanks for the help — NumberOneRobot, Aug 04 '14 at 18:04

score 0 · Answer 1 · answered Aug 04 '14 at 17:10

0

It's a GNU extension to the C ternary operator and expands to:

dict ? dict : @{ @"value" : value };

answered Aug 04 '14 at 17:10

Droppy

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Objective-C syntax: Is ?: part of a ternary operator?

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