[Solved] Consider the following code:public class User { public string Username { get; init; } } var user = new User { Username = "John" }; user.Username = "Jane";What will happen when this code runs? | C Sharp (C#)

C Sharp (C#) - Properties and Encapsulation

Consider the following code:

public class User {
    public string Username { get; init; }
}

var user = new User { Username = "John" };
user.Username = "Jane";

What will happen when this code runs?

ACompilation error on the second assignment

BUsername changes to "Jane" successfully

CRuntime exception is thrown

DThe initial value "John" is retained silently

Step-by-Step Solution

Solution:

Step 1: Understand init-only property behavior
Properties with init can only be assigned during object initialization (e.g., in object initializer or constructor).
Step 2: Analyze the code
The first assignment Username = "John" is valid during initialization. The second assignment user.Username = "Jane"; occurs after initialization, which is not allowed.
Step 3: Result
This causes a compilation error because the property cannot be assigned outside initialization.
Final Answer:
Compilation error on the second assignment -> Option A
Quick Check:
Init-only properties disallow post-initialization assignment [OK]

Quick Trick: Init-only properties can't be set after creation [OK]

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