True/false game

Question 1

2Next is a legal identifier.

Answer 1

False

Question 2

Non static methods can access static as well as non static methods of a class.

Answer 2

True

Question 3

do is a keyword so do() is not a valid method name.

Answer 3

True

Question 4

A class having no abstract method can’t still be abstract. But not vice-versa.

Answer 4

False

Question 5

A class having no abstract method can still be abstract. But not vice-versa.

Answer 5

True

Question 6

final static public void main (String[ ] arguments ) { } is valid.

Answer 6

True

Question 7

InputException and MemoryException are valid exceptions in Java

Answer 7

False

Question 8

FileNotFoundException and SecurityException are valid exceptions in Java

Answer 8

True

Question 9

If a.equals(b) returns true, b instanceof ClassOfA must always be true.

Answer 9

False

Question 10

The array consumes less memory than the ArrayList

Answer 10

True

Question 11

Accessing an element in an array is faster than in ArrayList.

Answer 11

True

Question 12

arrays implements Collection Interface

Answer 12

False

Question 13

Accessing implements Collection Interface

Answer 13

True

Question 14

A “default” constructor calls the no-args constructor of the super class.

Answer 14

True

Question 15

float f = -123; is valid

Answer 15

True

Question 16

It is not possible to create arrays of length zero

Answer 16

False

Question 17

A static method can’t access non-static instance variables of a class.

Answer 17

True

Question 18

StringBuilder sb1 = new StringBuilder() will create a StringBuilder object with no characters, but with an initial capacity to store 16 chars.

Answer 18

True

Question 19

StringBuilder sb1 = new StringBuilder(5*10) will create a StringBuilder object with a value 50.

Answer 19

False

Question 20

The insert method can be used to insert a character, number, or String at the start or end or a specified position of a StringBuilder.

Answer 20

True

Question 21

A class can’t define multiple main methods.

Answer 21

True

Question 22

More than one class in an application can define the main method.

Answer 22

True

Question 23

The main method may accept a String, a String array, or varargs (String… arg) as a method argument.

Answer 23

False

Question 24

The main method shouldn’t define an object of the class in which the main method itself is defined.

Answer 24

False

Question 25

The following is valid: static import java.lang.System.*;

Answer 25

False

Question 26

A variable can be synchronized

Answer 26

False

Question 27

A local variable can be volatile

Answer 27

False

Question 28

A constructor can be final

Answer 28

False

Question 29

A local variable can be transient

Answer 29

False

Question 30

Only member variables can be volatile

Answer 30

True

Question 31

Only member variables can be transient

Answer 31

True

Question 32

A constructor can be static

Answer 32

False

Question 33

A constructor can be abstract

Answer 33

False

Question 34

ArrayList extends java.util.AbstractList

Answer 34

True

Question 35

System.gc() suggests JVM to do garbage collection

Answer 35

True

Question 36

Static methods are not overridden, but shadowed

Answer 36

True

Question 37

strictfp is a keyword in java

Answer 37

True

Question 38

do is a keyword in java

Answer 38

True

Question 39

unsigned is a keyword in java

Answer 39

False

Question 40

A short can be assigned to a char without casting

Answer 40

False

Question 41

We cannot use this/super in static methods

Answer 41

True

Question 42

The variables of an interface are public, final and static

Answer 42

True

Question 43

The methods of an interface are public and abstract

Answer 43

True

Question 44

The methods of an interface can be final

Answer 44

False

Question 45

The methods of an interface can be static

Answer 45

False

Question 46

A derived class is abstract if it doesn’t implement all the abstract methods of it’s based class

Answer 46

True

Question 47

length() is a method of the Array class

Answer 47

False

Question 48

length() is a method of the String class

Answer 48

True

Question 49

StringBuilder has a method concat()

Answer 49

False

Question 50

String has a method append()

Answer 50

False

Question 51

StringBuilder has a method trim()

Answer 51

False

Question 52

The method append() of StringBuilder can take a String, char[ ], Boolean)

Answer 52

True

Question 53

The method substring() of String takes only int or char

Answer 53

True

Question 54

The class string has a method .intern()

Answer 54

True

Question 55

ArrayList can take duplicate values

Answer 55

True

Question 56

Method clone() of ArrayList creates a copy in a different object and the elements inside it point at the same place

Answer 56

True

Question 57

An else statement without an if block doesn’t compile

Answer 57

True

Question 58

An if statement without a block of code doesn’t compile

Answer 58

False

Question 59

Switch can take long, float or double

Answer 59

False

Question 60

Switch can take booleans

Answer 60

False

Question 61

Enhanced for loop cannot be used within a do-while loop

Answer 61

True

Question 62

Enhanced for loop has a counter variable for the position

Answer 62

False

Question 63

A class variable is not static

Answer 63

False

Question 64

The main method can throw exceptions

Answer 64

True

Question 65

Top-level classes cannot be private, protected or static

Answer 65

True

Question 66

An abstract class doesn’t need to have abstract methods

Answer 66

True

Question 67

Abstract methods can’t be in a normal class

Answer 67

True

Question 68

Abstract methods don’t have body

Answer 68

True

Question 69

An interface can be final

Answer 69

False

Question 70

A final method can be overridden

Answer 70

False

Question 71

Static methods can’t be abstract

Answer 71

True

Question 72

Static methods can use non-static variables

Answer 72

False

Question 73

A byte fits in an int

Answer 73

True

Question 74

= has precendence over ==

Answer 74

False

Question 75

Methods can return an interface

Answer 75

True

Question 76

ArrayIndexOutOfBoundsException is a subclass of IndexOutOfBoundsException

Answer 76

True

Question 77

To access a superclass variable that is shadowed you can use casting

Answer 77

True

Question 78

To access a superclass method that is shadowed you can use casting

Answer 78

False

Question 79

String has the method reverse()

Answer 79

False

Question 80

String has the method hasCode()

Answer 80

True

Question 81

An interface can extend another interface

Answer 81

True

Question 82

A class can be synchronized

Answer 82

False

Question 83

String class is final

Answer 83

True

Question 84

StringBuilder class is final

Answer 84

True

Question 85

Integer class is final

Answer 85

True

Question 86

java.lang.system class is final

Answer 86

True

Question 87

a constructor must throw the exception of its base class constructor or a super exception

Answer 87

True

Question 88

an overriding method can throw a super class exception of the base method’s exception

Answer 88

False

Question 89

an overriding method must return the same type if it’s a primitive

Answer 89

True

Question 90

an overriding method might return a different type

Answer 90

True

Question 91

ensureCapacity() is a method of StringBuilder

Answer 91

True

Question 92

setLength() is a method of StringBuilder

Answer 92

True

Question 93

if a base-class method is set as default, the overriding method can be set protected

Answer 93

True

Question 94

Only methods can be native

Answer 94

True

Question 95

Static methods may or may not be abstract

Answer 95

False

Question 96

& can have integral and Boolean operands but && can only have Boolean operands

Answer 96

True

Question 97

/, * and % have the same level of precedence

Answer 97

True

Question 98

% can only be used with integer operands

Answer 98

False

Question 99

You can define a member variable as private static final transient

Answer 99

True

Question 100

Integer values can be used in the condition of an if statement

Answer 100

False

Question 101

An overriding method may opt not to declare any throws clause even if the original method has a throws clause

Answer 101

True

Question 102

A class cannot override a super-class’ constructor

Answer 102

True

Question 103

Constructors cannot be abstract

Answer 103

True

Question 104

Constructors cannot have empty bodies

Answer 104

True

Question 105

Encapsulation helps make sure that clients have no accidental dependence on the choice of representation

Answer 105

True

Question 106

Encapsulation helps avoiding name clashes as internal variables are not visible outside

Answer 106

True

Question 107

Encapsulation makes sure that messages are sent to the right object at run time

Answer 107

False

Question 108

Dynamic binding is an outcome of polymorphism

Answer 108

True

Question 109

Encapsulation helps you inherit the properties of another class

Answer 109

False

Question 110

assert is a keyword in java

Answer 110

True

Question 111

const is a keyword in java

Answer 111

True

Question 112

Members of an interface may be static

Answer 112

True

Question 113

The methods of an interface are static

Answer 113

False

Question 114

instanceof is a java operator

Answer 114

True

Question 115

You can sort the elements of an ArrayList using Collection.sort()

Answer 115

True

Question 116

You must specify the class of the objects you want to store in an ArrayList when you declare a variable of type ArrayList

Answer 116

False

Question 117

StackOverflowError and OutOfMemoryError ar subclasses of VirtualMachineError

Answer 117

True

Question 118

new StringBuilder() creates an object of StringBuilder with capacity for 16 chars

Answer 118

True

Question 119

MemoryOutOfBounds exception is a subclass of RuntimeException

Answer 119

False

Question 120

An abstract class cannot implement an interface

Answer 120

False

Question 121

A concrete class can be extended by an abstract or a concrete class

Answer 121

True

Question 122

double/float/long/boolean are invalid in a switch

Answer 122

True

Question 123

Is it possible to create arrays of length zero

Answer 123

True