本文翻譯自http://fuckingblocksyntax.com/
作為區域性變數：
returnType(^blockName)(parameterTypes) = ^returnType(parameters) {...};
複製程式碼作為屬性：
@property (nonatomic, copy) returnType (^blockName)(parameterTypes);
複製程式碼作為引數：
- (void)someMethodThatTakesABlock:(returnType (^nullability)(parameterTypes))blockName;
複製程式碼作為方法呼叫引數：
[someObject someMethodThatTakesABlock:^returnType (parameters) {...} ];
複製程式碼作為typedef
typedef returnType (^TypeName)(parameterTypes);
TypeName blockName = ^returnType(parameters) {...};
複製程式碼