Yield statement

Yield keyword is used in an iterator block to calculate the value for the enumerator object.

Can be understand by an example

1. class Program

2. {

3.        static void Main(string[] args)

4.        {

5.            foreach (int i in GetInt())

6.                Console.WriteLine("Got " + i.ToString());

7.        }

8.        public static IEnumerable<int> GetInt()

9.        {

10.            for (int i = 0; i < 5; i++)
{

11.               yield return i;

if(i==3)
yield break;

}

12.        }

}

As soon as control reach at line no 11 for i=0. It returns the value of i to caller.

And control reached to line no 5 again thereafter print its value.

Again call the same function GetInt but this time loop does not start from starting it start from where we have leave it i.e for i=1 and again when it reach to line no 11 it returns the value of i to caller. This process repeat until the GetInt() loop ends.

So output will be

0

1

2

3

4

This output we can without using yield statement but main point is that while using yield no need to iterate the whole loop if not required.