JIGSAW

What method would you use to get the current date and time using the Calendar class?

• Calendar.getCurrentDateTime()

• Calendar.getInstance().getTime()

• Calendar.currentTime()

• Calendar.now().getDate()

Explain how to split a string into tokens using StringTokenizer. What is the default delimiter?

• The default delimiter is a period.

• The default delimiter is a semicolon.

• The default delimiter is a comma.

• The default delimiter is whitespace.

What is the purpose of the Iterator interface in Java collections?

• To remove elements from a collection

• To store elements in a collection

• To sort elements in a collection

• The purpose of the Iterator interface in Java collections is to provide a standard way to iterate over elements in a collection.

How do you add a key-value pair to a Hashtable in Java?

• hashtable.insert(key, value);

• hashtable.put(key, value);

• hashtable.add(key, value);

• hashtable.append(key, value);

Describe the role of the Collections framework in Java. Why is it important?

• The Collections framework is a part of the Java Virtual Machine (JVM) architecture.

• The Collections framework in Java is essential for efficient data management and manipulation, providing various data structures and algorithms.

• The Collections framework is only used for graphical user interface components.

• It is primarily focused on database connectivity and management.

How can you iterate over a collection using an Iterator?

• Use a for loop to access each element directly.

• Use an Iterator to call hasNext() and next() methods to traverse the collection.

• Call the size() method to get the collection length.

• Use a while loop without checking for hasNext() method.

How do you remove an element from a List in Java?

• list.remove(index);

• list.delete(index);

• list.erase(index);

• list.pop(index);

What method is used to check if a collection contains a specific element in Java?

• collection.exists(element);

• collection.has(element);

• collection.include(element);

• collection.contains(element);

How do you create a new ArrayList in Java?

• ArrayList list = new ArrayList();

• ArrayList list = new ArrayList<>();

• ArrayList list = new ArrayList();

• ArrayList list = new ArrayList(10);

What is the difference between a List and a Set in Java?

• A List is unordered, while a Set is ordered.

• A List allows duplicate elements, while a Set does not.

• A List can only store objects, while a Set can store primitives.

• There is no difference; they are the same.