I keep seeing block declarations like this:
typedef returnType (^TypeName)(parameterTypes);
And I would like to know, why would I declare a block as a typedef?
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MikeCastro26
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1To make it easier to use in method parameter definitions and variable declarations. This is useful reference: http://goshdarnblocksyntax.com/ – Anna Dickinson Dec 02 '14 at 16:40
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So, I can just declare it as a typedef and use it wherever I want, instead of declaring it as a local variable or a method parameters? @AnnaDickinson – MikeCastro26 Dec 02 '14 at 16:54
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Yup, as long as the typedef is defined in that scope (I.e. Its header is imported). – Anna Dickinson Dec 02 '14 at 16:56
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Sweet! Now I get it :), thank you very much!! @AnnaDickinson. – MikeCastro26 Dec 02 '14 at 17:01
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Declare a property with block type, and you'll be most grateful for the typedef. – gnasher729 Dec 02 '14 at 17:33
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You do it that way to reduce the likelihood of typos and make the code more readable. For an extreme example, see my answer here: Syntax to define a Block that takes a Block and returns a Block in Objective-C
