CSharp Programming

CSharp Programming

Collection Classes has 16 Questions
Which of the following statements are correct about an ArrayList collection that implements the IEnumerable interface?
  1. The ArrayList class contains an inner class that implements the IEnumerator interface.
  2. An ArrayList Collection cannot be accessed simultaneously by different threads.
  3. The inner class of ArrayList can access ArrayList class's members.
  4. To access members of ArrayList from the inner class, it is necessary to pass ArrayList class's reference to it.
  5. 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
How many enumerators will exist if four threads are simultaneously working on an ArrayList object?

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

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

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

True
False
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'.
This is a perfectly workable code.
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
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");
Which of the following is the correct way to access all elements of the Queue collection created using the C#.NET code snippet given below?
Queue q = new Queue(); 
q.Enqueue("Sachin"); 
q.Enqueue('A'); 
q.Enqueue(false); 
q.Enqueue(38); 
q.Enqueue(5.4);

IEnumerator e;

e = Stack.GetEnumerator();

while (e.MoveNext()) Console.WriteLine(e.Current);

IEnumerable e;

e = q.GetEnumerator();

while (e.MoveNext()) Console.WriteLine(e.Current);

IEnumerator e;

e = q.GetEnumerable();

while (e.MoveNext()) Console.WriteLine(e.Current);

IEnumerator e;

e = Queue.GetEnumerator();

while (e.MoveNext()) Console.WriteLine(e.Current);

Which of the following is NOT an interface declared in System.Collections namespace?

IComparer
Enumerable
Enumerator
IDictionaryComparer
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
Which of the following is an ordered collection class?
  1. Map
  2. Stack
  3. Queue
  4. BitArray
  5. HashTable

1 only
2 and 3 only
4 and 5 only
All of the above
Which of the following is the correct way to find out the number of elements currently present in an ArrayList Collection called arr?

arr.Count
arr.GrowSize
arr.MaxIndex
arr.Capacity
  1. Which of the following statements are correct about a HashTable collection?
  2. It is a keyed collection.
  3. It is a ordered collection.
  4. It is an indexed collection.
  5. It implements a IDictionaryEnumerator interface in its inner class.
  6. The key - value pairs present in a HashTable can be accessed using the Keys and Values properties of the inner class that implements the IDictionaryEnumerator interface.

1 and 2 only
1, 2 and 3 only
4 and 5 only
1, 4 and 5 only
Which of the following is the correct way to access all elements of the Stack collection created using the C#.NET code snippet given below?
Stack st = new Stack();
st.Push(11);
st.Push(22);
st.Push(-53);
st.Push(33);
st.Push(66);

IEnumerable e;

e = st.GetEnumerator();

while (e.MoveNext())Console.WriteLine(e.Current);

IEnumerator e;

e = st.GetEnumerable();

while (e.MoveNext())Console.WriteLine(e.Current);

IEnumerator e;

e = st.GetEnumerator();

while (e.MoveNext()) Console.WriteLine(e.Current);

IEnumerator e;

e = Stack.GetEnumerator();

while (e.MoveNext()) Console.WriteLine(e.Current);

Which of the following statements are correct about the Collection Classes available in Framework Class Library?

Elements of a collection cannot be transmitted over a network.
Elements stored in a collection can be retrieved but cannot be modified.
It is not easy to adopt the existing Collection classes for newtype of objects.
They use efficient algorithms to manage the collection, thereby improving the performance of the program.