working with blocks and function which takes block as a parameter in objective c

how to create a block in objective c

define a block in .h file 

/*here i created a block 

addPhysicsBody is the name of block

^ without is block can’t be completed 

so block is defined ^addPhysicsBody

typedef void (^addPhysicsBody)(CGPoint);

where void is return type and CGpoint is parameter

where bolded part is a parameter taken by block

2)  step 2

@property (copy) addPhysicsBody clickBlock;

add block as a property and please remember that this property is copy 

 because a block needs to be copied to keep track of its captured state outside of the original scope by apple 

define a function in .h file that takes block as a parameter this is necessary while creating block with function 

- (void)getPhysicsBody:(void (^)(CGPoint))finishBlock;

where above bolded part is block with its parameter 

- (void)getPhysicsBodyAtScene:(void (^)(CGPoint))finishBlock{

  

    //block passed to self.clickBlock property

    self.clickBlock=finishBlock;

  

}

4)step 4

 pass block

pass parameter to block  self.clickBlock

  self.clickBlock(location);

note use above syntax where you want to fire the block

5)

capture block

 [self getPhysicsBodyAtScene:^(CGPoint points) {

        //

        NSLog(@"%f",points.x);

    }];