Using statement for resource cleanup in C Sharp (C#) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to ensure the StreamReader is properly disposed after use.

C Sharp (C#)

using ([1] reader = new StreamReader("file.txt"))
{
    string content = reader.ReadToEnd();
    Console.WriteLine(content);
}

Drag options to blanks, or click blank then click option'

AStreamReader

BFileStream

CMemoryStream

DBinaryReader

Attempts:

3 left

💡 Hint

Common Mistakes

Using a type that does not implement IDisposable.

Using a stream type that reads bytes instead of characters.

The using statement requires a disposable resource. Here, StreamReader is the correct type to read text files and be disposed automatically.

2fill in blank

medium

Complete the code to open a file stream with automatic cleanup.

C Sharp (C#)

using ([1] fileStream = new FileStream("data.bin", FileMode.Open))
{
    // Read data
}

Drag options to blanks, or click blank then click option'

AFileStream

BStreamReader

CMemoryStream

DBinaryReader

Attempts:

3 left

💡 Hint

Common Mistakes

Using StreamReader when binary access is needed.

Using MemoryStream which is not connected to a file.

FileStream is used to open a file for reading or writing bytes and supports disposal with using.

3fill in blank

hard

Fix the error in the using statement to properly dispose the resource.

C Sharp (C#)

using [1] = new StreamWriter("output.txt");
writer.WriteLine("Hello World");

Drag options to blanks, or click blank then click option'

AStreamWriter

BStreamWriter writer

Cvar writer

Dwriter

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the variable name.

Using only the type without variable name.

In C# 8.0 and later, the using declaration syntax requires the variable to be declared with var or explicit type and variable name. Here, var writer is correct.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that stores file lengths for files larger than 1000 bytes.

C Sharp (C#)

var fileLengths = new Dictionary<string, long>()
{
    { [1], [2] }
};

Drag options to blanks, or click blank then click option'

A"file.txt"

Bnew FileInfo("file.txt").Length

Cnew FileInfo("file.txt").Name

D"length"

Attempts:

3 left

💡 Hint

Common Mistakes

Using the file name property incorrectly.

Using a string literal for the file length.

The dictionary key is the file name as a string, and the value is the file length obtained from FileInfo.Length.

5fill in blank

hard

Fill all three blanks to create a using statement that reads all lines from a file and prints them.

C Sharp (C#)

using ([1] reader = new [2]("log.txt"))
{
    string line;
    while ((line = reader.[3]()) != null)
    {
        Console.WriteLine(line);
    }
}

Drag options to blanks, or click blank then click option'

AStreamReader

BReadLine

CStreamWriter

DFileStream

Attempts:

3 left

💡 Hint

Common Mistakes

Using StreamWriter instead of StreamReader.

Using FileStream which reads bytes, not lines.

Using a method other than ReadLine to read lines.

StreamReader is used to read text lines from a file. The method ReadLine() reads one line at a time.