C# how yield works

It represents a state machine that implements GetNumbers(). Use the yield return statement to return a value, or yield break to end the iteration. Hopefully by now how to use yield is clear, even if why you would use it and how does it work is not yet. Lets explore the example from above for a little longer. First of all both examples can pretty much be used inside your code interchangeably.

In this post I want to explain what it does and what its applications are. When you use the yield contextual keyword in a statement, you indicate that the metho operator, or get accessor in which it appears is an iterator. In other words “ yield ” keyword moves control of the program to and fro between caller and the collection. But here, the function is to call back in the loop containing the yield return function that just ended.

From here we can imagine an action that is rather abstract, but can be useful in some cases, to help keep code concise and tight. Some requirements for the use of yield return Do not put yield in an unsafe block. Now that you get how it works , jump back to the yield statement. Anything you want to happen after the wait goes after the yield statement and everything you want to happen before, goes before the yield statement. Based on the value produce with the yield return , consumer can write some logic based on their need.

Leave a Reply Cancel reply. Operating Kubernetes Clusters and Applications Safely. Execution is restarted from that location the next time that the iterator function is called.

You can use a yield break statement to end the iteration. ToList() on the result of a method that yields, it will work as if you returned a single list, thus defeating the purpose of yield. NET Framework Reference Source Code. A yield return statement can be used only if the return type is IEnumerator, IEnumeratorT, IEnumerable, or IEnumerableT.

The yield statement is used in an iterator block (§) to yield a value to the enumerator object (§1) or enumerable object (§1) of an iterator or to signal the end of the iteration. The compiler generates a class to implement the behavior that is expressed in the iterator block. When your co-routine returns an object by calling yield return new SomeType(), Unity will check its type. And when next time you call, it will continue it process with the last yield call. I understand the principle of coroutines.

Ich sehe diesen Thread zum Thema. Schlüsselwort in einer realen Situation verwenden würde. Yield Keyword-Wert hinzugefügt? Can somebody show me a pr.

Ich finde, dass dein Beispiel den Vorteil von yield nicht besonders gut herausarbeitet. Die Alternative zu yield ist für mich immer die Verwendung eines Arrays oder einer Liste, die zum Befüllen. You can find detailed information about how the yield keyword works under the hood here.

Rate this: Please or sign in to vote. Have you been using yield in interesting ways? I was reading about how iterators work (the yield returns) and I came across this code This is the method with the yiel.

While yield break is propably the best answer and it really does not matter since you always can do Items. Count() to check if greater zero or even do for each on your empty result there could be situations where it does matter if your result is an empty list or nothing at all and you still want to utilize the power of yield. The return part of yield -return is potentially misleading to those not familiar with the yield -return statement, because return by itself unconditionally transfers control out of a method. Writing yield return we indicate that current method returns IEnumerable, which elements are of yield return expressions. I could spend a whole post on how cool yield is, but you can find that elsewhere.

For a cool example, you can see the Fibonacci series implemented using yield. Early documentation for the yield -return mechanism made the statement sound exotic and mysterious. The main idea of yield construction is to generate a collection item on request and return it to the enumerator consumer immediately.

It behaves differently then the Javascript version of yield. RPC with return type IEnumerator so that yield will work properly. RPC, make a dummy function with return type void.

People have remarked that this is not intuitive, that people calling your method may not know that enumerating the result twice will call the method twice. I’m quite excited about the new capabilities it will bring. If the work you have is CPU-bound and you care about responsiveness, use async and await but spawn the work off on another thread with Task. If the work is appropriate for concurrency and parallelism, you should also consider using the Task Parallel Library. Additionally, you should always measure the execution of your code.

IEnumerable 介面的物件集合時, 是使用 yield return 來取代原來的 return 指令。 Code： using System.