_Strategies to Get Rid of NullReferenceException.png

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NullReferenceException is an error that programmers frequently encounter, and it is often referred to as the Billion Dollar Mistake. This course is designed to assist you in avoiding this error.

You will begin by gaining an understanding of when NullReferenceException is thrown and how to prevent null in your code. You’ll also learn how to employ nullable operators to simplify null checks and use nullable references and the Option wrapper to identify problematic code blocks. Finally, you will explore avoiding NullReferenceException when using specific LINQ methods and designing your C# classes.

Upon completing this course, you’ll have gained the necessary knowledge and skills to effectively address and avoid NullReferenceException issues in your projects.

Mastering NullReferenceException Prevention in C#

# Key points

The message below makes more sense now.

```
"Object reference not set to an instance of an object"
```



It means we have an object reference that, instead of pointing to an actual object, is uninitialized and points to `null`.

To fix the `NullReferenceException`, we shouldn't catch it. Instead, we should prevent it by checking for `null` and defending against it. We can simplify our `null` checks with the `?.`, `??`, and `??=` operators.

Review what you have learned in this course.

Wrap Up!

Key points