Async file reading and writing in C Sharp (C#) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to read all text asynchronously from a file.

C Sharp (C#)

string content = await File.[1]("example.txt");

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AReadFileAsync

BReadTextAsync

CReadAllTextAsync

DReadAsyncText

Attempts:

3 left

💡 Hint

Common Mistakes

Using a method name that does not exist in the File class.

Confusing synchronous and asynchronous methods.

The method ReadAllTextAsync reads the entire content of a file asynchronously as a string.

2fill in blank

medium

Complete the code to write text asynchronously to a file.

C Sharp (C#)

await File.[1]("output.txt", "Hello World!");

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AWriteAllTextAsync

BWriteTextAsync

CWriteFileAsync

DWriteAsyncText

Attempts:

3 left

💡 Hint

Common Mistakes

Using a method name that does not exist in the File class.

Confusing synchronous and asynchronous methods.

The method WriteAllTextAsync writes the entire string content asynchronously to a file.

3fill in blank

hard

Fix the error in the async method declaration.

C Sharp (C#)

public async [1] ReadFileAsync(string path)
{
    return await File.ReadAllTextAsync(path);
}

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Avoid

BTask<string>

Casync

DTask

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'void' as return type for async methods that return a value.

Using 'Task' instead of 'Task' when returning a string.

The method returns a Task<string> because it is asynchronous and returns a string result.

4fill in blank

hard

Fill both blanks to create a dictionary with file names as keys and their sizes as values asynchronously.

C Sharp (C#)

var fileSizes = new Dictionary<string, long>();
foreach (var file in files)
{
    var info = new FileInfo(file);
    fileSizes[[1]] = await Task.Run(() => info.[2]);
}

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Afile

BLength

CName

DSize

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong property name for file size.

Using the wrong variable for the dictionary key.

The key is the file path stored in file, and the size is obtained from the Length property of FileInfo.

5fill in blank

hard

Fill all three blanks to asynchronously read multiple files and store their contents in a dictionary with file names as keys.

C Sharp (C#)

var contents = new Dictionary<string, string>();
foreach (var [1] in fileList)
{
    contents[[2]] = await File.[3]([2]);
}

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AfileName

BReadAllTextAsync

Cfile

Attempts:

3 left

💡 Hint

Common Mistakes

Using inconsistent variable names.

Using a synchronous method instead of an async one.

The loop variable is fileName, used as the dictionary key and passed to ReadAllTextAsync to read the file content asynchronously.