Lambda with captures (closures) in C Sharp (C#) - Mini Project: Build & Apply

Lambda with captures (closures) in C#

📖 Scenario: Imagine you are creating a simple calculator that can remember a number and add it to other numbers later.

🎯 Goal: You will build a small program that uses a lambda function to remember a number (capture it) and add it to new numbers when called.

📋 What You'll Learn

Create an integer variable called baseNumber with the value 10

Create a lambda function called addBase that takes an integer parameter x and returns the sum of baseNumber and x

Call the lambda function addBase with the value 5 and store the result in a variable called result

Print the value of result

💡 Why This Matters

🌍 Real World

Closures like this are useful when you want to create small functions that remember some data without needing to pass it every time.

💼 Career

Understanding closures helps in writing clean, reusable code in many programming jobs, especially when working with events, callbacks, or functional programming styles.

1

Create the base number

Create an integer variable called baseNumber and set it to 10.

C Sharp (C#)

int baseNumber = 0;
// Your code here

Need a hint?

Use int baseNumber = 10; to create the variable.

2

Create the lambda function with capture

Create a lambda function called addBase that takes an integer parameter x and returns the sum of baseNumber and x.

C Sharp (C#)

int baseNumber = 10;
Func addBase = null;
// Your code here

Need a hint?

Use Func<int, int> and a lambda expression like x => baseNumber + x.

3

Call the lambda function

Call the lambda function addBase with the value 5 and store the result in a variable called result.

C Sharp (C#)

int baseNumber = 10;
Func addBase = x => baseNumber + x;
int result = 0;
// Your code here

Need a hint?

Call addBase(5) and assign it to result.

4

Print the result

Print the value of the variable result using Console.WriteLine.

C Sharp (C#)

int baseNumber = 10;
Func addBase = x => baseNumber + x;
int result = addBase(5);
// Your code here

Need a hint?

Use Console.WriteLine(result); to show the output.