Multiple generic parameters in C Sharp (C#) - Step-by-Step Execution

Concept Flow - Multiple generic parameters

Define class with <T1, T2>

↓

Create instance with types

↓

Use T1 and T2 in methods

↓

Access properties of T1 and T2

↓

Output results using both types

This flow shows how a class with two generic types is defined, instantiated with specific types, and used to access and output values of both types.

Execution Sample

C Sharp (C#)

class Pair<T1, T2> {
  public T1 First;
  public T2 Second;
  public Pair(T1 first, T2 second) {
    First = first;
    Second = second;
  }
}

var p = new Pair<int, string>(10, "hello");
Console.WriteLine($"{p.First}, {p.Second}");

Defines a generic Pair class with two types, creates an instance with int and string, then prints the values.

Execution Table

Step	Action	T1 Value	T2 Value	Output
1	Define class Pair<T1, T2>	-	-	-
2	Create instance Pair<int, string>(10, "hello")	10	hello	-
3	Assign First = 10	10	-	-
4	Assign Second = "hello"	-	hello	-
5	Print values	10	hello	10, hello
6	End of program	-	-	-

💡 Program ends after printing the values of both generic parameters.

Variable Tracker

Variable	Start	After Step 2	After Step 3	After Step 4	Final
p.First	-	-	10	10	10
p.Second	-	-	-	hello	hello

Key Moments - 2 Insights

Why do we use two generic parameters instead of one?

Using two generic parameters lets us store and work with two different types independently, as shown in steps 2-4 where First and Second hold different types.

How does the compiler know what types T1 and T2 are?

When creating the instance (step 2), we specify the types explicitly (int and string), so the compiler replaces T1 with int and T2 with string.

Visual Quiz - 3 Questions

Look at the execution table at step 3, what is the value of p.First?

A 10

B "hello"

C null

D undefined

💡 Hint

Check the 'T1 Value' column at step 3 in the execution table.

At which step does the program output the values of both generic parameters?

A Step 4

B Step 5

C Step 2

D Step 6

💡 Hint

Look for the 'Output' column in the execution table.

If we changed the instance to Pair<double, bool>(3.14, true), what would p.Second be after step 4?

A 3.14

B false

C true

D null

💡 Hint

Refer to variable_tracker and how Second holds the second generic type value.

Concept Snapshot

Multiple generic parameters allow a class or method to work with two or more types.
Syntax: class ClassName<T1, T2> { ... }
Create instance: new ClassName<Type1, Type2>(...)
Each generic parameter acts independently.
Use to store or process different types together.

Full Transcript

This example shows how to define a class with two generic parameters T1 and T2. We create an instance of this class with int and string types. The variables First and Second hold values of these types. The program prints both values. The execution table traces each step: defining the class, creating the instance, assigning values, and printing output. The variable tracker shows how p.First and p.Second change. Key moments clarify why two generics are useful and how the compiler knows the types. The quiz tests understanding of values at different steps and how changing types affects variables.