Indexer declaration in C Sharp (C#) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare an indexer that returns an int.

C Sharp (C#)

public int this[[1] index] { get { return index; } }

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Aint

Bstring

Cbool

Ddouble

Attempts:

3 left

💡 Hint

Common Mistakes

Using a return type instead of parameter type inside the brackets.

Using a type that is not valid for an indexer parameter.

The indexer parameter must have a type, here it is int because the index is an integer.

2fill in blank

medium

Complete the code to declare a read-only indexer that returns a string.

C Sharp (C#)

public string this[int index] { [1] { return "value"; } }

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Aset

Bprivate

Cinit

Dget

Attempts:

3 left

💡 Hint

Common Mistakes

Using set instead of get for reading values.

Using invalid accessor keywords.

The get accessor is used to return a value from the indexer.

3fill in blank

hard

Fix the error in the indexer declaration by completing the code.

C Sharp (C#)

public int this[int index] { get { return [1]; } }

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Athis

Bindex

Cvalue

Dnull

Attempts:

3 left

💡 Hint

Common Mistakes

Returning value inside a get accessor.

Returning this which is invalid here.

The indexer should return the parameter index to work correctly.

4fill in blank

hard

Fill both blanks to declare an indexer with get and set accessors.

C Sharp (C#)

public string this[int index] { [1] { return data[index]; } [2] { data[index] = value; } }

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Aget

Bset

Cinit

Dprivate

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping get and set keywords.

Using invalid accessor names.

The get accessor returns the value, and the set accessor assigns a value.

5fill in blank

hard

Fill all three blanks to declare an indexer that returns the uppercase key if value is not empty.

C Sharp (C#)

public Dictionary<string, string> data = new Dictionary<string, string>();
public string this[[1] key] {
    get {
        return data.ContainsKey(key) && data[key] [2] "" ? key.[3]() : null;
    }
}

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

Astring

B!=

CToUpper

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong parameter type like int.

Using == instead of != in the condition.

Using incorrect method name for uppercase conversion.

The indexer parameter type is string. The condition checks if the value is not empty using !=. The key is converted to uppercase with ToUpper().