How reflection bypasses compile-time safety in C Sharp (C#) - Try It Yourself

How reflection bypasses compile-time safety

📖 Scenario: Imagine you have a simple class with a private field. Normally, you cannot access this private field directly because the compiler protects it. But using reflection, you can peek inside and change it, even though the compiler says you shouldn't.

🎯 Goal: You will create a class with a private field, then use reflection to access and modify that private field. This shows how reflection can bypass compile-time safety checks.

📋 What You'll Learn

Create a class called Person with a private string field name set to "Alice"

Create an instance of Person called person

Use reflection to get the private field name from person

Change the value of name to "Bob" using reflection

Print the value of the private field name after modification

💡 Why This Matters

🌍 Real World

Reflection is used in many tools and frameworks to inspect and modify objects at runtime, such as serializers, dependency injectors, and testing tools.

💼 Career

Understanding reflection helps developers debug, test, and extend applications dynamically, and also teaches about the limits of compile-time safety.

1

Create the Person class with a private field

Create a class called Person with a private string field name initialized to "Alice".

C Sharp (C#)

// Your code here

Need a hint?

Use private string name = "Alice"; inside the Person class.

2

Create an instance of Person

Create an instance of the Person class called person.

C Sharp (C#)

public class Person
{
    private string name = "Alice";
}

// Your code here

Need a hint?

Use Person person = new Person(); to create the object.

3

Use reflection to get the private field name

Use reflection to get the private field name from the person instance. Store it in a variable called field.

C Sharp (C#)

public class Person
{
    private string name = "Alice";
}

Person person = new Person();

// Your code here

Need a hint?

Use typeof(Person).GetField("name", BindingFlags.NonPublic | BindingFlags.Instance) to get the private field.

4

Change the private field value and print it

Use the field variable to set the value of the private field name in person to "Bob". Then print the new value of the private field name using reflection.

C Sharp (C#)

using System.Reflection;

public class Person
{
    private string name = "Alice";
}

Person person = new Person();
FieldInfo field = typeof(Person).GetField("name", BindingFlags.NonPublic | BindingFlags.Instance);

// Your code here

Need a hint?

Use field.SetValue(person, "Bob") to change the value and Console.WriteLine(field.GetValue(person)) to print it.