Record inheritance in C Sharp (C#) - Step-by-Step Execution

Concept Flow - Record inheritance

Define base record

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Define derived record : base

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Create instance of derived record

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Access base and derived properties

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Use with-expressions to copy and modify

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Print or compare records

Shows how a derived record inherits properties and behavior from a base record, allowing creation, access, and modification.

Execution Sample

C Sharp (C#)

public record Person(string Name, int Age);
public record Employee(string Name, int Age, string Position) : Person(Name, Age);

var emp = new Employee("Alice", 30, "Developer");
Console.WriteLine(emp);

Defines a base record Person and a derived record Employee, creates an Employee instance, and prints it.

Execution Table

Step	Action	Evaluation	Result
1	Define record Person with Name and Age	Person record created	Person(Name, Age)
2	Define record Employee inheriting Person, adds Position	Employee record created	Employee(Name, Age, Position) : Person(Name, Age)
3	Create Employee instance emp with Name='Alice', Age=30, Position='Developer'	emp = new Employee("Alice", 30, "Developer")	emp.Name = 'Alice', emp.Age = 30, emp.Position = 'Developer'
4	Print emp	Console.WriteLine(emp)	Employee { Name = Alice, Age = 30, Position = Developer }
5	Use with-expression to create emp2 from emp with Position='Manager'	var emp2 = emp with { Position = "Manager" }	emp2.Name = 'Alice', emp2.Age = 30, emp2.Position = 'Manager'
6	Print emp2	Console.WriteLine(emp2)	Employee { Name = Alice, Age = 30, Position = Manager }
7	Compare emp and emp2	emp == emp2	False
8	Compare emp with itself	emp == emp	True

💡 All steps executed; program ends after printing and comparisons.

Variable Tracker

Variable	Start	After Step 3	After Step 5	Final
emp	null	{Name: 'Alice', Age: 30, Position: 'Developer'}	{Name: 'Alice', Age: 30, Position: 'Developer'}	{Name: 'Alice', Age: 30, Position: 'Developer'}
emp2	null	null	{Name: 'Alice', Age: 30, Position: 'Manager'}	{Name: 'Alice', Age: 30, Position: 'Manager'}

Key Moments - 3 Insights

Why does Employee inherit Name and Age even though they are not declared again?

Because Employee inherits from Person, it automatically has the Name and Age properties defined in Person, as shown in steps 1 and 2 of the execution_table.

What does the 'with' expression do in step 5?

It creates a new Employee record copying all properties from emp but changes Position to 'Manager', as shown in step 5 of the execution_table.

Why are emp and emp2 not equal even though they share Name and Age?

Because Position differs ('Developer' vs 'Manager'), the records are not equal, as shown in step 7 of the execution_table.

Visual Quiz - 3 Questions

Look at the execution_table at step 3, what are the values of emp's properties?

A Name='Alice', Age=30, Position='Developer'

B Name='Alice', Age=30, Position='Manager'

C Name='Bob', Age=25, Position='Developer'

D Name='Alice', Age=25, Position='Developer'

💡 Hint

Check the 'Result' column in step 3 of the execution_table.

At which step does the 'with' expression create a new record with a changed Position?

A Step 4

B Step 6

C Step 5

D Step 7

💡 Hint

Look for the step describing 'with-expression' in the execution_table.

According to variable_tracker, what is the value of emp2 after step 5?

A {Name: 'Alice', Age: 30, Position: 'Developer'}

B {Name: 'Alice', Age: 30, Position: 'Manager'}

C null

D {Name: 'Bob', Age: 30, Position: 'Manager'}

💡 Hint

Check the 'After Step 5' column for emp2 in variable_tracker.

Concept Snapshot

Record inheritance in C#:
- Use 'record Derived(...) : Base(...)' syntax
- Derived inherits properties from Base
- Create instances with all properties
- Use 'with' to copy and modify
- Records compare by value automatically

Full Transcript

This example shows how record inheritance works in C#. We define a base record Person with Name and Age. Then we define Employee that inherits Person and adds Position. When we create an Employee instance, it has all three properties. Printing the record shows all properties. Using the 'with' expression creates a new record copying existing values but changing specified ones. Comparing records checks all properties for equality. This trace helps understand how inheritance and value equality work with records.