Checked and unchecked arithmetic in C Sharp (C#) - Mini Project: Build & Apply

Checked and unchecked arithmetic

📖 Scenario: You are working on a simple calculator program that needs to handle arithmetic operations carefully. Sometimes numbers can get too big and cause errors. C# lets you control this with checked and unchecked blocks.

🎯 Goal: Build a program that shows how checked and unchecked affect arithmetic overflow in C#.

📋 What You'll Learn

Create two integer variables with large values

Create a checked block to add the numbers and catch overflow

Create an unchecked block to add the numbers without overflow error

Print the results of both operations

💡 Why This Matters

🌍 Real World

Handling arithmetic overflow is important in financial, scientific, and gaming applications where numbers can get very large.

💼 Career

Understanding checked and unchecked arithmetic helps developers write safer C# code that avoids unexpected crashes or data corruption.

1

Create two integer variables with large values

Create two integer variables called largeNumber1 and largeNumber2 with values int.MaxValue and 1 respectively.

C Sharp (C#)

# Create two integer variables called largeNumber1 and largeNumber2 with values int.MaxValue and 1

Need a hint?

Use int.MaxValue to get the largest integer value.

2

Create a checked block to add the numbers and catch overflow

Create a variable called checkedResult inside a checked block that adds largeNumber1 and largeNumber2. Use a try-catch block to catch OverflowException and set checkedResult to 0 if overflow occurs.

C Sharp (C#)

int largeNumber1 = int.MaxValue;
int largeNumber2 = 1;
// Create checkedResult inside a checked block with try-catch

Need a hint?

Use checked { } to detect overflow and try-catch to handle it.

3

Create an unchecked block to add the numbers without overflow error

Create a variable called uncheckedResult inside an unchecked block that adds largeNumber1 and largeNumber2 without throwing an exception.

C Sharp (C#)

int largeNumber1 = int.MaxValue;
int largeNumber2 = 1;
int checkedResult;
try
{
    checked
    {
        checkedResult = largeNumber1 + largeNumber2;
    }
}
catch (OverflowException)
{
    checkedResult = 0;
}
// Create uncheckedResult inside an unchecked block

Need a hint?

Use unchecked( ... ) to allow overflow without error.

4

Print the results of both operations

Write two Console.WriteLine statements to print checkedResult and uncheckedResult with labels "Checked result:" and "Unchecked result:" respectively.

C Sharp (C#)

int largeNumber1 = int.MaxValue;
int largeNumber2 = 1;
int checkedResult;
try
{
    checked
    {
        checkedResult = largeNumber1 + largeNumber2;
    }
}
catch (OverflowException)
{
    checkedResult = 0;
}
int uncheckedResult = unchecked(largeNumber1 + largeNumber2);
// Print checkedResult and uncheckedResult with labels

Need a hint?

Use Console.WriteLine to show the results clearly.