R4RIN – MCQs, Mock Tests | Java Java Mcq Question Set 6

Which of these class can generate an array which can increase and decrease in size automatically?

1. DynamicsList()
2. DynamicList()
3. ArrayList()
4. LinkedList()

✅ Correct Answer: 3

Which of these method can be used to increase the capacity of ArrayList object manually?

1. ensureCapacity()
2. increasecapacity()
3. increaseCapacity()
4. Capacity()

✅ Correct Answer: 1

Which of these method of ArrayList class is used to obtain present size of an object?

1. index()
2. size()
3. capacity()
4. length()

✅ Correct Answer: 2

Which of these methods can be used to obtain a static array from an ArrayList object?

1. Array()
2. toArray()
3. covertArray()
4. covertoArray()

✅ Correct Answer: 1

Which of these standard collection classes implements a linked list data structure?

1. LinkedList
2. HashSet
3. AbstractSet
4. AbstractList

✅ Correct Answer: 1

Which of these method is used to add an element to the start of a LinkedList object?

1. addFirst()
2. AddFirst()
3. first()
4. add()

✅ Correct Answer: 1

Which of these method of HashSet class is used to add elements to its object?

1. Add()
2. add()
3. insert()
4. addFirst()

✅ Correct Answer: 2

Which of these methods can be used to delete the last element in a LinkedList object?

1. delete()
2. remove()
3. deleteLast()
4. removeLast()

✅ Correct Answer: 4

Which of these object stores association between keys and values?

1. Map
2. Array
3. String
4. Hash table

✅ Correct Answer: 1

Which of these method is used to reduce the capacity of an ArrayList object?

1. trimTosize()
2. trimToSize()
3. trimSize()
4. trim()

✅ Correct Answer: 2

Which of these classes provide implementation of map interface?

1. LinkedList
2. HashMap
3. ArrayList
4. DynamicList

✅ Correct Answer: 2

Which of these method is used to remove all keys/values pair from the invoking map?

1. remove()
2. delete()
3. removeAll()
4. clear()

✅ Correct Answer: 1

Which of these method Map class is used to obtain an element in the map having specified key ?

1. get()
2. search()
3. look()
4. set()

✅ Correct Answer: 2

Which of these methods can be used to obtain set of all keys in a map?

1. keySet()
2. getAll()
3. getKeys()
4. keyall()

✅ Correct Answer: 1

Which of these method is used add an element and corresponding key to a map?

1. set()
2. put()
3. add()
4. redo()

✅ Correct Answer: 2

Which of these standard collection classes implements all the standard functions on list data structure?

1. HashSet
2. AbstractSet
3. Array
4. LinkedList

✅ Correct Answer: 3

Which of these method is used to make all elements of an equal to specified value?

1. fill()
2. add()
3. set()
4. all()

✅ Correct Answer: 1

Which of these method of Array class is used sort an array or its subset?

1. bubblesort()
2. binarysort()
3. insert()
4. sort()

✅ Correct Answer: 4

Which of these methods can be used to search an element in a list?

1. binaryserach()
2. find()
3. sort()
4. get()

✅ Correct Answer: 1

Which of these method is used to change an element in a LinkedList Object?

1. add()
2. change()
3. redo()
4. set()

✅ Correct Answer: 3

Which of these standard collection classes implements all the standard functions on list data structure?

1. HashSet
2. AbstractSet
3. LinkedList
4. Array

✅ Correct Answer: 4

Which of these classes implements Set interface?

1. LinkedList
2. DynamicList
3. HashSet
4. ArrayList

✅ Correct Answer: 3

Which of these class object can be used to form a dynamic array?

1. ArrayList
2. Map
3. Both a & b
4. Vector

✅ Correct Answer: 3

Which of these are legacy classes?

1. Vector
2. Hashtable
3. Stack
4. All of the above

✅ Correct Answer: 4

All of the above

1. HashMap
2. Enumeration
3. Hashtable
4. Map

✅ Correct Answer: 2

What is the name of data member of class Vector which is used to store number of elements in the vector?

1. elements
2. elementCount
3. length
4. capacity

✅ Correct Answer: 2

Which of these methods is used to add elements in vector at specific location?

1. addElement()
2. AddElement()
3. set()
4. add()

✅ Correct Answer: 1

Which of these class object uses key to store value?

1. Dictionary
2. Map
3. Hashtable
4. All of the above

✅ Correct Answer: 4

Which of these method is used to insert value and its key?

1. set()
2. put()
3. addElement()
4. insertElement()

✅ Correct Answer: 2

Which of these is the interface of legacy is implemented by Hashtable and Dictionary classes?

1. Map
2. HashMap
3. Hashtable
4. Enumeration

✅ Correct Answer: 1

Which of these is a class which uses String as a key to store the value in object?

1. ArrayList
2. Properties
3. Dictionary
4. Array

✅ Correct Answer: 2

Which of these methods is used to retrieve the elements in properties object at specific location?

1. Elementat()
2. getProperty()
3. ElementAt()
4. get()

✅ Correct Answer: 2

Which of these class object has architecture similar to that of array?

1. Hashtable
2. Bitset
3. Map
4. All of the above

✅ Correct Answer: 2

Which of these method is used to make a bit zero specified by the index?

1. clear()
2. put()
3. set()
4. remove()

✅ Correct Answer: 1

Which of these method is used to calculate number of bits required to hold the BitSet object?

1. numberofBits()
2. indexes()
3. length()
4. size()

✅ Correct Answer: 3

Which of these is a method of class Date which is used to search weather object contains a date before the specified date?

1. contains()
2. after()
3. compareTo()
4. before()

✅ Correct Answer: 4

Which of these methods is used to retrieve elements in BitSet object at specific location?

1. get()
2. Elementat()
3. getProperty()
4. ElementAt()

✅ Correct Answer: 1

Which of these is a process of writing the state of an object to a byte stream?

1. Externalization
2. Serialization
3. File Filtering
4. All of the above

✅ Correct Answer: 2

Which of these process occur automatically by java run time system?

1. Garbage collection
2. Serialization
3. File Filtering
4. All of the above

✅ Correct Answer: 2

Which of these interface extends DataOutput interface?

1. Externalization
2. Serializable
3. ObjectInput
4. ObjectOutput

✅ Correct Answer: 4

Which of these is a method of ObjectOutput interface used to finalize the output state so that any buffers are cleared?

1. flush()
2. close()
3. fflush()
4. clear()

✅ Correct Answer: 1

Which of these is method of ObjectOutput interface used to write the object to input or output stream as required?

1. StreamWrite()
2. writeObject()
3. Write()
4. write()

✅ Correct Answer: 2

Which of these is a process of extracting/removing the state of an object from a stream?

1. Externalization
2. Deserialization
3. Serialization
4. File Filtering

✅ Correct Answer: 2

Which of these process occur automatically by java run time system?

1. Serialization
2. Deserialization
3. Memory allocation
4. All of the above

✅ Correct Answer: 4

Which of these is an interface for control over serialization and deserialization?

1. Externalization
2. Serializable
3. FileFilter
4. ObjectInput

✅ Correct Answer: 1

Which of these interface extends DataInput interface?

1. Serializable
2. ObjectInput
3. Externalization
4. ObjectOutput

✅ Correct Answer: 2

Which of these is a method of ObjectInput interface used to deserialize an object from a stream?

1. Object WriteObject()
2. void close()
3. Object readObject()
4. int read()

✅ Correct Answer: 3

Which of these class extend InputStream class?

1. ObjectInputStream
2. ObjectStream
3. ObjectInput
4. ObjectOutput

✅ Correct Answer: 1

Which of these method can be used to make the main thread to be executed last among all the threads?

1. join()
2. stop()
3. sleep()
4. call()

✅ Correct Answer: 3

Which of these method is used to find out that a thread is still running or not?

1. Alive()
2. checkRun()
3. run()
4. isAlive()

✅ Correct Answer: 4