Versions

[{“Name”:“2.0”,“GroupName”:null},{“Name”:“Modern”,“GroupName”:null}]

Syntax

// Declare as a local variable:     

returnType (^blockName)(parameterType1, parameterType2, ...) = ^returnType(argument1, argument2, ...) {...};

// Declare as a property:    

@property (nonatomic, copy, nullability) returnType (^blockName)(parameterTypes);

// Declare as a method parameter:

\\- (void)someMethodThatTakesABlock:(returnType (^nullability)(parameterTypes))blockName;

// Declare as an argument to a method call:

[someObject someMethodThatTakesABlock:^returnType (parameters) {...}];

// Declare as a typedef:

typedef returnType (^TypeName)(parameterTypes);

TypeName blockName = ^returnType(parameters) {...};

// Declare a C function return a block object:

BLOCK_RETURN_TYPE (^function_name(function parameters))(BLOCK_PARAMETER_TYPE);

Remarks

Blocks are specified by the Language Specification for Blocks for C, Objective-C, C++ and Objective-C++.

Additionally, the Blocks ABI is defined by the Block Implementation Specification.