Working with JSON files in C Sharp (C#) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to read a JSON file into a string.

C Sharp (C#)

string jsonString = File.[1]("data.json");

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

AWriteAllLines

BWriteAllText

CReadAllLines

DReadAllText

Attempts:

3 left

💡 Hint

Common Mistakes

Using WriteAllText instead of ReadAllText will overwrite the file.

ReadAllLines returns a string array, not a single string.

The File.ReadAllText method reads the entire content of a file as a string, which is perfect for reading JSON files.

2fill in blank

medium

Complete the code to deserialize JSON string into an object of type Person.

C Sharp (C#)

Person person = JsonSerializer.[1]<Person>(jsonString);

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

AParse

BDeserialize

CSerialize

DConvert

Attempts:

3 left

💡 Hint

Common Mistakes

Using Serialize instead of Deserialize will convert an object to JSON, not the other way.

Parse is not a method in JsonSerializer.

The JsonSerializer.Deserialize<T> method converts a JSON string into an object of type T.

3fill in blank

hard

Fix the error in the code to serialize an object to JSON string.

C Sharp (C#)

string jsonString = JsonSerializer.[1](person);

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

ADeserialize

BParse

CSerialize

DConvert

Attempts:

3 left

💡 Hint

Common Mistakes

Using Deserialize will cause a compile-time error because it expects a JSON string input.

Parse and Convert are not methods of JsonSerializer.

The Serialize method converts an object into a JSON string.

4fill in blank

hard

Fill both blanks to write a JSON string to a file asynchronously.

C Sharp (C#)

await File.[1]Async("output.json", jsonString[2]);

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

AWriteAllText

BReadAllText

CWriteAllLines

D, CancellationToken.None

Attempts:

3 left

💡 Hint

Common Mistakes

Using ReadAllTextAsync instead of WriteAllTextAsync will read instead of write.

Omitting the cancellation token parameter may cause errors in some contexts.

The WriteAllTextAsync method writes text to a file asynchronously. The second blank is a cancellation token parameter, which can be CancellationToken.None if no cancellation is needed.

5fill in blank

hard

Fill all three blanks to create a dictionary from JSON and filter keys with length > 3.

C Sharp (C#)

var filtered = jsonDict.Where(kv => kv.Key.[1] > 3).ToDictionary(kv => kv.[2], kv => kv.[3]);

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

ALength

BKey

CValue

DCount

Attempts:

3 left

💡 Hint

Common Mistakes

Using Count instead of Length for string length.

Swapping Key and Value in ToDictionary parameters.

We use Length to get the length of the key string, then select Key and Value to build the filtered dictionary.