We’ve all been there. You’re deep in a debugging session, hunting down a bug in a complex collection of objects. You fire up the Visual Studio watch window, expand your list, and this is what greets you:

Zero context. Total mystery.

To figure out which class schedule or section is which, you have to click and expand every single object, scroll past dozens of properties, and manually hunt for the ClassCode or Instructor. It’s tedious, it breaks your mental flow, and honestly, it’s a waste of time.

Most .NET developers just accept this as the tax you pay for debugging. But it doesn’t have to be that way.

With exactly one line of code, you can transform that wall of text into this:

The secret? A highly underutilized attribute called DebuggerDisplay.

What is DebuggerDisplay?

[DebuggerDisplay] is a built-in meta-attribute in the System.Diagnostics namespace. It allows you to explicitly tell Visual Studio (or JetBrains Rider) exactly how a class, property, or field should render in the data tips, watch windows, and locals windows during an active debug session.

Instead of defaulting to the standard ToString() representation—which usually just spits out the full namespace and class name—DebuggerDisplay lets you interpolate real-time object values into a clean, readable string.

How to Implement It (The Easy Way)

Implementing this trick is incredibly simple. You just wrap your desired string format inside the attribute and place it right above your class definition. Use curly braces {} to reference the properties of that class.

Here is a quick look at the “Before and After” of a standard CourseClass definition.

The Standard Way

Without the attribute, you get the default namespace text.

public class CourseClass
{
    public string ClassCode { get; set; }
    public string CourseName { get; set; }
    public string Instructor { get; set; }
    public int EnrolledStudents { get; set; }
}

The Upgraded, 10x Productive Way

By adding the DebuggerDisplay attribute, you instantly surface the most critical data to the top level of your IDE.

using System.Diagnostics;

[DebuggerDisplay("Class {ClassCode}: {CourseName} ({Instructor}) - {EnrolledStudents} Students")]
public class CourseClass
{
    public string ClassCode { get; set; }
    public string CourseName { get; set; }
    public string Instructor { get; set; }
    public int EnrolledStudents { get; set; }
}

Now, the moment you hover over a CourseClass object or view it inside a generic List<CourseClass>, you instantly know exactly which record you are looking at without a single extra click.

Tips for Advanced Usage

While the basic setup covers 90% of your daily use cases, DebuggerDisplay has a few extra superpowers that make it even more robust.

1. Avoid Putting Logic in the Attribute

It can be tempting to write complex expressions inside the attribute string, like this: [DebuggerDisplay("{EnrolledStudents > 30 ? \"Full\" : \"Open\"}")]

Don’t do this. It makes the attribute messy to read and harder to maintain. Instead, create a private, debug-only property or method inside your class and point the attribute to it.

[DebuggerDisplay("{DebuggerSummary,nq}")]
public class CourseClass
{
    public string ClassCode { get; set; }
    public string CourseName { get; set; }
    public string Instructor { get; set; }
    public int EnrolledStudents { get; set; }

    // "nq" stands for "No Quotes" to keep the IDE output clean
    private string DebuggerSummary => $"Class {ClassCode}: {CourseName} ({Instructor}) - {EnrolledStudents} Students";
}

2. What is that ,nq suffix?

By default, the IDE might wrap string values in quotation marks when displaying them. Adding ,nq (which stands for No Quotes) at the end of your expression tells the debugger to drop the quotation marks, leaving your watch window looking pristine and highly readable.

Why Not Just Override ToString()?

This is the most common question devs ask: Why not just override the ToString() method on the class?

While overriding ToString() does change how an object looks in the debugger, it also changes how that object behaves in your actual application logic. If your code relies on ToString() for logging, UI data-binding, or string serialization, modifying it just for debugging can introduce accidental side effects or break existing functionality.

DebuggerDisplay is strictly for tooling. It is completely stripped out of your production logic and only exists to make your life as a developer easier.

Make It a Habit

The next time you find yourself clicking through endless nested dropdowns in your IDE’s watch window, take a 5-second timeout. Add [DebuggerDisplay] to the top of that problematic class.

Your future self and anyone else reviewing or debugging your codebase will thank you.