Quick Answer

Implement property accessors in C#.

Understanding the Issue

C# properties provide controlled access to class fields with get/set accessors, enabling validation and encapsulation.

The Problem

This code demonstrates the issue:

Csharp Error 
// Need to expose fields with validation

The Solution

Here's the corrected code:

Csharp Fixed 
// Basic property
private string _name;
public string Name {
    get { return _name; }
    set { _name = value; }
}

// Auto-property (C# 3+)
public int Age { get; set; }

// Read-only property
public DateTime Created { get; } = DateTime.Now;

// Property with validation
private decimal _price;
public decimal Price {
    get => _price;
    set => _price = value >= 0 ? value : throw new ArgumentOutOfRangeException();
}

// Expression-bodied property (C# 6+)
public string FullName => $"{FirstName} {LastName}";

// Init-only property (C# 9+)
public string Address { get; init; }

Key Takeaways

Use properties instead of public fields for better encapsulation.