Blocks in Objective c

Blocks are Objective c`s anonymous functions . 

Block is a self-contained, autonomous code fragment, existing always in the scope of another programming structure , e.g. body of a method.

Blocks helps you to :

1)  Reduce code

2)  Write more cleaner code

3)  More reliable code

Block basic syntax : 

                        ReturnType (^Name of the block) (Parameters)

• ReturnType : Any datatype supported by Objective c 

• ^Name of the block : Name of the block is always preceded by the carret symbol (^).

• Parameters : Parameters which you want to pass on the block.

Block example : 

	int (^myBlock) (int ,int) = ^(int first , int second) {
	return first / second;
	};
	int result = myBlock(22 ,2 );
	NSLog(@"Printing result --- %i",result);
	// Output is 11 in the console ....

view raw BlockExample hosted with ❤ by GitHub

Blocks used for array enumeration  :


Arrays enumeration using blocks is fastest .

>> Use this code for faster enumeration of arrays

	NSArray *myArray = @[@"Saurabh",@"Dutta",@"iOS",@"Developer",@"9988207247"];
	[myArray enumerateObjectsUsingBlock:^(id _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
	NSLog(@"Object at index %lu is %@",(unsigned long)idx,obj);
	}];

view raw arrayEnumeration hosted with ❤ by GitHub

Blocks Advantages:


1) Blocks can do same as methods but methods can`t do all the tasks like blocks

2) Blocks can be parsed to other functions.

3) Blocks are used in multi-threading

4) Blocks have faster array enumeration as compared to for in and for loops .

5) Blocks are simpler to read.


That`s a small introduction to blocks in objective c. More complex part will be covered in the future tutorials .



Thank you :)