Set operations (Union, Intersect, Except) in C Sharp (C#) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a union of two sets.

C Sharp (C#)

var set1 = new HashSet<int> {1, 2, 3};
var set2 = new HashSet<int> {3, 4, 5};
var unionSet = set1.[1](set2);
Console.WriteLine(string.Join(", ", unionSet));

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

AExcept

BUnionWith

CIntersect

DUnion

Attempts:

3 left

💡 Hint

Common Mistakes

Using UnionWith which modifies the original set instead of returning a new one.

Using Intersect which returns only common elements.

The Union method returns a new set that contains all elements from both sets.

2fill in blank

medium

Complete the code to find the intersection of two sets.

C Sharp (C#)

var setA = new HashSet<string> {"apple", "banana", "cherry"};
var setB = new HashSet<string> {"banana", "date", "fig"};
var common = setA.[1](setB);
Console.WriteLine(string.Join(", ", common));

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

AExcept

BUnion

CIntersect

DUnionWith

Attempts:

3 left

💡 Hint

Common Mistakes

Using Except which returns elements only in the first set.

Using Union which returns all elements from both sets.

The Intersect method returns elements that appear in both sets.

3fill in blank

hard

Fix the error in the code to get the difference of two sets.

C Sharp (C#)

var firstSet = new HashSet<int> {10, 20, 30, 40};
var secondSet = new HashSet<int> {30, 40, 50};
var difference = firstSet.[1](secondSet);
Console.WriteLine(string.Join(", ", difference));

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

AIntersect

BExcept

CUnionWith

DUnion

Attempts:

3 left

💡 Hint

Common Mistakes

Using Intersect which returns common elements.

Using Union which returns all elements combined.

The Except method returns elements in the first set that are not in the second set.

4fill in blank

hard

Fill both blanks to create a set of fruits that are in set1 but not in set2, then print the count.

C Sharp (C#)

var set1 = new HashSet<string> {"apple", "banana", "cherry", "date"};
var set2 = new HashSet<string> {"banana", "date", "fig"};
var result = new HashSet<string>(set1.[1](set2));
Console.WriteLine(result.[2]);

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

AExcept

BCount

CLength

DIntersect

Attempts:

3 left

💡 Hint

Common Mistakes

Using Intersect instead of Except.

Using Length which is not a property of HashSet.

Except returns elements in set1 not in set2. Count gives the number of elements in the result.

5fill in blank

hard

Fill the blanks to create a union of two sets, remove elements in the third set, and print the final elements.

C Sharp (C#)

var setA = new HashSet<int> {1, 2, 3};
var setB = new HashSet<int> {3, 4, 5};
var setC = new HashSet<int> {2, 5};
var union = setA.[1](setB);
var finalSet = union.[2](setC);
Console.WriteLine(string.Join(", ", finalSet));

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

AUnion

BExcept

CIntersect

DUnionWith

Attempts:

3 left

💡 Hint

Common Mistakes

Using Intersect instead of Union.

Using UnionWith where a method returning a new set is needed.

Union combines setA and setB. Then Except removes elements in setC from the union.