Why exception handling is needed in C Sharp (C#) - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to catch an exception.

C Sharp (C#)

try {
    int result = 10 / [1];
} catch (DivideByZeroException) {
    Console.WriteLine("Cannot divide by zero.");
}

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A0

B1

C2

D10

Attempts:

3 left

💡 Hint

Common Mistakes

Using a non-zero number does not cause an exception.

Dividing by zero causes an exception. Catching it prevents the program from crashing.

2fill in blank

medium

Complete the code to throw an exception when input is invalid.

C Sharp (C#)

if (age < 0) {
    throw new [1]("Age cannot be negative.");
}

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AArgumentException

BArgumentNullException

CInvalidOperationException

DDivideByZeroException

Attempts:

3 left

💡 Hint

Common Mistakes

Using exceptions unrelated to argument errors.

ArgumentException is used when an argument is invalid, like a negative age.

3fill in blank

hard

Fix the error in the catch block to handle any exception.

C Sharp (C#)

try {
    int[] numbers = new int[3];
    int x = numbers[5];
} catch ([1]) {
    Console.WriteLine("An error occurred.");
}

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AIndexOutOfRangeException

BNullReferenceException

CDivideByZeroException

DException

Attempts:

3 left

💡 Hint

Common Mistakes

Catching only specific exceptions misses others.

Catching Exception handles all exceptions, including unexpected ones.

4fill in blank

hard

Fill both blanks to handle a file error and display a message.

C Sharp (C#)

try {
    var text = System.IO.File.ReadAllText([1]);
} catch ([2]) {
    Console.WriteLine("File not found.");
}

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A"data.txt"

BFileNotFoundException

CIOException

D"input.txt"

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong exception type or missing quotes around filename.

Reading "data.txt" may cause FileNotFoundException if the file is missing.

5fill in blank

hard

Fill all three blanks to catch an exception and print its message.

C Sharp (C#)

try {
    int num = int.Parse([1]);
} catch ([2] ex) {
    Console.WriteLine([3]);
}

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A"abc"

BFormatException

Cex.Message

D"123"

Attempts:

3 left

💡 Hint

Common Mistakes

Parsing a valid number does not cause exception.

Parsing "abc" causes FormatException. Printing ex.Message shows the error.