String interpolation and formatting in C Sharp (C#) - Mini Project: Build & Apply

String interpolation and formatting

📖 Scenario: You are creating a simple program to display product information in a store. You want to show the product name, quantity, and price in a clear and friendly way.

🎯 Goal: Build a program that uses string interpolation and formatting to display product details with price shown as currency and quantity as a number.

📋 What You'll Learn

Create variables for product name, quantity, and price

Use a format string with string interpolation to combine these variables

Format the price as currency

Format the quantity as a number without decimals

Print the final formatted string

💡 Why This Matters

🌍 Real World

Displaying product information clearly in shopping apps or inventory systems helps customers and staff understand prices and stock easily.

💼 Career

Knowing how to format strings and numbers is essential for creating user-friendly interfaces and reports in software development.

1

Create product variables

Create a string variable called productName and set it to "Chocolate Bar". Create an integer variable called quantity and set it to 5. Create a double variable called price and set it to 1.99.

C Sharp (C#)

// Your code here

Need a hint?

Use string for text, int for whole numbers, and double for decimal numbers.

2

Create a formatted message variable

Create a string variable called message that uses string interpolation to combine productName, quantity, and price. Format price as currency using :C and quantity as a number with no decimals using :N0 inside the interpolation.

C Sharp (C#)

string productName = "Chocolate Bar";
int quantity = 5;
double price = 1.99;
// Your code here

Need a hint?

Use $"...{variable:format}..." to insert variables with formatting.

3

Add a method to create the message

Create a method called CreateMessage that returns a string. Inside it, return the same formatted string using productName, quantity, and price with the same formatting as before. Use the existing variables from the outer scope.

C Sharp (C#)

string productName = "Chocolate Bar";
int quantity = 5;
double price = 1.99;
string message = $"Product: {productName}, Quantity: {quantity:N0}, Price: {price:C}";
// Your code here

Need a hint?

Define a method with string CreateMessage() and return the formatted string inside.

4

Print the formatted message

Use Console.WriteLine to print the message variable. Then print the result of calling the CreateMessage() method.

C Sharp (C#)

string productName = "Chocolate Bar";
int quantity = 5;
double price = 1.99;
string message = $"Product: {productName}, Quantity: {quantity:N0}, Price: {price:C}";

string CreateMessage()
{
    return $"Product: {productName}, Quantity: {quantity:N0}, Price: {price:C}";
}
// Your code here

Need a hint?

Use Console.WriteLine(message); and Console.WriteLine(CreateMessage()); to print.