Stream vs async stream behavior in C Sharp (C#) - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to read all bytes from a stream synchronously.

C Sharp (C#)

using var stream = new MemoryStream(data);
byte[] buffer = new byte[stream.Length];
stream.[1](buffer, 0, buffer.Length);

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

AReadAsync

BRead

CWrite

DFlush

Attempts:

3 left

💡 Hint

Common Mistakes

Using ReadAsync instead of Read for synchronous reading.

Using Write which is for writing data, not reading.

The Read method reads bytes synchronously from the stream into the buffer.

2fill in blank

medium

Complete the code to asynchronously read bytes from a stream.

C Sharp (C#)

using var stream = new MemoryStream(data);
byte[] buffer = new byte[stream.Length];
await stream.[1](buffer, 0, buffer.Length);

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AReadAsync

BRead

CWriteAsync

DFlushAsync

Attempts:

3 left

💡 Hint

Common Mistakes

Using Read instead of ReadAsync for asynchronous reading.

Using WriteAsync which is for writing data asynchronously.

The ReadAsync method reads bytes asynchronously from the stream into the buffer.

3fill in blank

hard

Fix the error in the async stream reading loop.

C Sharp (C#)

await foreach (var chunk in stream.[1]())
{
    Process(chunk);
}

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AReadChunksAsync

BReadAllBytesAsync

CReadAllAsync

DReadAsync

Attempts:

3 left

💡 Hint

Common Mistakes

Using ReadAsync which returns a Task, not an async stream.

Using method names that do not exist on Stream.

The ReadChunksAsync method returns an async stream of chunks to iterate over asynchronously.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps words to their lengths only if length is greater than 3.

C Sharp (C#)

var lengths = new Dictionary<string, int> { { [1], [2] } };
foreach (var word in words)
{
    if (word.Length > 3)
        lengths[word] = word.Length;
}

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A"word"

Bword.Length

Cword

Dword.Length > 3

Attempts:

3 left

💡 Hint

Common Mistakes

Using a string literal "word" as key instead of the variable word.

Using a condition as a value instead of the length.

The key is the word itself, and the value is its length.

5fill in blank

hard

Fill all three blanks to create an async enumerable that yields uppercase words longer than 4 characters.

C Sharp (C#)

async IAsyncEnumerable<string> GetFilteredWords(IEnumerable<string> words)
{
    foreach (var [1] in words)
    {
        if ([2] > 4)
            yield return [3];
    }
}

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Aword

Bword.Length

Cword.ToUpper()

Dwords

Attempts:

3 left

💡 Hint

Common Mistakes

Using the collection variable instead of the loop variable.

Yielding the original word instead of the uppercase version.

We iterate over each word, check if its length is greater than 4, and yield the uppercase version.