Exploring the yield keyword

The yield keyword is contextual and is used with iterators. The following are the two ways to use the yield keyword:

• yield return <expression>;: This returns the value of the expression.
• yield break;: This will exit from the iteration

When using the yield keyword, there are some restrictions to be aware of. These are as follows:

• You cannot use the yield keyword in unsafe blocks of code.
• You cannot use the ref or out parameters for methods, operators, or accessors.
• You cannot return using the yield keyword in a try-catch block.
• You cannot use the yield keyword in anonymous methods.
• You can use yield in a try block if the try block is followed by the finally block.
• You can use yield break in a try-catch block but not the finally block.

In this section, we are going to add a class that shows the yield keyword in action. Then, we will benchmark two ways to return an IEnumerable<long> consisting...