What is the difference between a field and a property in C#?

Below is a concise overview of how fields and properties differ in C#. Understanding these differences is crucial for writing clean, encapsulated, and maintainable code.

Fields

Direct Data Storage
- A field represents a variable that is directly stored in an object’s memory (for reference types) or in the type’s memory (for static fields).
- Example:
```
public class Person
{
    public string name; // Field
}
```
Access
- Fields are typically accessed directly unless you decide to encapsulate them.
- Fields can be public, private, protected, etc. However, using public fields is discouraged in most cases because it breaks encapsulation.
No Built-in Validation or Logic
- A field doesn’t inherently allow you to run custom logic (e.g., validation) when it’s read or modified.
- You’d need to manually add that logic wherever the field is used.

Properties

Encapsulation with Getters/Setters

A property provides controlled access to a private field, often referred to as a backing field.
Properties can include get and set accessors, letting you insert validation, transformation, or additional logic in these methods.

Example:

public class Person
{
    private string name; // Backing field

    public string Name
    {
        get { return name; }
        set
        {
            // Basic validation
            if (string.IsNullOrWhiteSpace(value))
                throw new ArgumentException("Name cannot be empty!");
            name = value;
        }
    }
}

Automatic Properties
- C# offers auto-properties, which allow you to skip manually creating the backing field if you don’t need extra logic:
```
public class Book
{
    public string Title { get; set; } // Auto-property
}
```
- You can also initialize auto-properties inline:
```
public string Title { get; set; } = "Default Title";
```
Flexibility and Future-proofing
- If requirements change—say, you need validation or logging when setting a property—you can add that logic without changing how consumers use the property.
- This preserves the public interface of your class while keeping the ability to evolve internal behavior.

Summary

Fields are low-level storage variables. They’re straightforward but can break encapsulation if made public.
Properties are the recommended approach for exposing data, letting you implement validation, logic, and maintain consistent access patterns.

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Grokking System Design Fundamentals
System Design Primer The Ultimate Guide:
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Additionally, check out the DesignGurus.io YouTube channel for free tutorials and insights on software engineering, system design, and interview preparation. By understanding when and how to use fields versus properties, you’ll ensure your code remains both robust and extensible.

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