C# - Collection Classes Questions and Answers

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C# Collection Classes questions with answers are highly useful for mastering data storage and manipulation techniques in programming. Topics like Lists, Dictionaries, Queues, and HashSets are frequently tested in programming interviews and coding assessments. Practicing programming questions and answers with explanations helps students improve their understanding of C# data structures and performance optimization. Such programming MCQs and problem-based aptitude questions are commonly asked in technical interviews and placement tests conducted by companies like Microsoft, TCS, and Infosys. Strengthen your skills through C# programming test practice and learn to use collections efficiently.

Questions on data collections in C language. Broaden skills with arrays and pointers

C# - Collection Classes

Showing 10 of 14 questions

1. Which of the following statements are correct about an ArrayList collection that implements the IEnumerable interface? The ArrayList class contains an inner class that implements the IEnumerator interface.     An ArrayList Collection cannot be accessed simultaneously by different threads.     The inner class of ArrayList can access ArrayList class's members.     To access members of ArrayList from the inner class, it is necessary to pass ArrayList class's reference to it.     Enumerator's of ArrayList Collection can manipulate the array.

  • 1 and 2 only
  • 1 and 3 and 4 only
  • 2 and 5 only
  • All of the above
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2. How many enumerators will exist if four threads are simultaneously working on an ArrayList object?

  • 1
  • 3
  • 2
  • 4
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3. In which of the following collections is the Input/Output index-based?  Stack     Queue     BitArray     ArrayList     HashTable

  • 1 and 2 only
  • 3 and 4 only
  • 5 only
  • 1, 2 and 5 only
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4. In which of the following collections is the Input/Output based on a key?     Map     Stack     BitArray     HashTable     SortedList

  • 1 and 2 only
  • 2 and 3 only
  • 1, 2 and 3 only
  • 4 and 5 only
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5. In a HashTable Key cannot be null, but Value can be.

  • True
  • False
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6. Which of the following statements are correct about the C#.NET code snippet given below? Stack st = new Stack(); st.Push("hello"); st.Push(8.2); st.Push(5); st.Push('b'); st.Push(true);

  • Dissimilar elements like "hello", 8.2, 5 cannot be stored in the same Stack collection.
  • Boolean values can never be stored in Stack collection.
  • In the fourth call to Push(), we should write "b" in place of 'b'.
  • To store dissimilar elements in a Stack collection, a method PushAnyType() should be used in place of Push().
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7. Which of the following statements are correct about the Stack collection?   1  It can be used for evaluation of expressions.    2.All elements in the Stack collection can be accessed using an enumerator.    3.It is used to maintain a FIFO list.    4. All elements stored in a Stack collection must be of similar type.     5.Top-most element of the Stack collection can be accessed using the Peek() method.

  • 1 and 2 only
  • 3 and 4 only
  • 1, 2 and 5 only
  • All of the above
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8. A HashTable t maintains a collection of names of states and capital city of each state. Which of the following is the correct way to find out whether "Kerala" state is present in this collection or not?

  • t.ContainsKey("Kerala");
  • t.HasValue("Kerala");
  • t.HasKey("Kerala");
  • t.ContainsState("Kerala");
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9. Which of the following is NOT an interface declared in System.Collections namespace?

  • IComparer
  • Enumerable
  • Enumerator
  • IDictionaryComparer
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10. Suppose value of the Capacity property of ArrayList Collection is set to 4. What will be the capacity of the Collection on adding fifth element to it?

  • 4
  • 8
  • 16
  • 32
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