Learn Microsoft AI demonstrates the new null-conditional assignment feature in C# 14 and .NET 10, showing how these updates can help you write safer, cleaner C# code.

C# 14 New Feature: Null-Conditional Assignment in .NET 10

Learn Microsoft AI presents a walkthrough of a C# 14 feature introduced in .NET 10: null-conditional assignment using ?. and ?[] as assignment targets. This update allows you to write expressions such as myObj?.Property = value; and myArray?[index] = value;, so the assignment only occurs if the target is not null.

What is Null-Conditional Assignment?

  • Traditionally, assigning values through an object or array required explicit null checks to avoid exceptions.
  • C# 14 enables the use of null-conditional (?., ?[]) directly on the assignment’s left-hand side.
  • Benefit: Only evaluates the right-hand side if the assignment target is not null, delivering cleaner and safer code.

Example Usage

person?.Name = "Alex";
items?[3] = "New Value";
  • If person or items is null, no assignment or exception occurs.

Advantages

  • Reduces boilerplate null checks
  • Prevents NullReferenceException in common patterns
  • Keeps code more readable and concise

When to Use

  • Working with optional objects or collections
  • Refactoring older codebases for safety improvements

Learn More

  • This feature is available starting in C# 14 with .NET 10.
  • See official documentation and sample projects for real-world examples.

Author: Learn Microsoft AI