What is the primary concept of polymorphism in object-oriented programming?

Providing a single interface to entities of different types

What is the primary purpose of an interface in Java?

To define required method signatures for implementing classes."

What does method overriding mean in Java?

a subclass redefines a method of its superclass wth an identical signature

How is the "super" keyword used in Java?

To access members of a superclass from within a sub-class

Is it mandatory for a subclass to override all methods of its superclass in Java?

No, it is not mandatory for a superclass method to be overridden.

Does Java support multiple inheritance for classes?

No, Java does not support multiple inheritance for classes.

What is the primary purpose of public getter/setter methods in Java?

To provide access to private class fields

In Java, what is the purpose of access modifiers?

To specify the declared accessibility of classes or members

What is the primary difference between value types and reference types in Java?

Value types store dta in their own memory while referenc types use pointers

What does it mean when a method in Java is declared as "static"?

It belongs to the class and is shared by all instances of the class.

What is the primary purpose of exception handling in Java?

To handle unexpected or exceptional situations during program execution

Which of the following is a feature of an abstract class in Java?

It may contain abstract methods and cannot be instantiated directly.

In Java, what does the keyword "void" in a method header indicate?

The method does not return a value to its caller.

what happens when an integer variable "num" is copied to another variable "copyNum" via the assign

The two variables become unrelated.

What is the purpose of the "length" attribute in Java arrays?

To define the total number of elements in an array

In polymorphism, what does it mean when a variable of a superclass can refer to an object of a sub-type subclass

It demonstrates polymorphic behavior.

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Object Oriented Programming - Part 2

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Questions 24

Answers

1
In Java, what does it mean when it is stated that arrays are "zero-indexed"?
Arrays use negative indexes.
Arrays start at the index 1.
Arrays have no indexes.
Arrays start at the index 0.
2
When copying an integer variable to another variable, what happens in value type operations?
Original variable is deleted
Variables share memory
Variables become unrelated
New values are assigned
3
What is the primary concept of polymorphism in object-oriented programming?
Encapsulation
Inheritance
Method overloading
Providing a single interface to entities of different types
4
What is the primary purpose of an interface in Java?
To create multiple instances of a class
To provide default implementations for methods
To prevent class inheritance
To define required method signatures for implementing classes."
5
What is the order of visibility from least to most restrictive among the access modifiers in Java?
Private, public, protected
Public, protected, private
Private, protected, public
Protected, private, public
6
What does method overriding mean in Java?
It is a way to create private methods in a class.
a subclass redefines a method of its superclass wth an identical signature
It is a way to create new methods in a subclass.
It is a keyword used to annotate methods.
7
What is the primary purpose of an abstract class in Java?
To be instantiated directly without overriding
To prevent the creation of objects from it
To provide implementations for all methods
To allow multiple inheritance
8
How is the "super" keyword used in Java?
To indicate a method's return type
To access members of a superclass from within a sub-class
To declare a variable
To create new instances of classes
9
How does modifying an object in reference type operations differ from value type operations?
Modifying objects isn't allowed
Affects all variables in value type operations
Affects all variables
Affects only one variable
10
Is it mandatory for a subclass to override all methods of its superclass in Java?
Yes, only abstract methods must be overridden.
Yes, all methods must be overridden.
No, a subclass cannot override any methods.
No, it is not mandatory for a superclass method to be overridden.
11
Does Java support multiple inheritance for classes?
No, Java supports multiple inheritance for interfaces only.
No, Java does not support multiple inheritance for classes.
Yes, Java supports multiple inheritance for both classes and interfaces.
Yes, Java supports multiple inheritance for classes.
12
What is the primary purpose of public getter/setter methods in Java?
To perform mathematical operations
To define constructors
To provide access to private class fields
To create new objects
13
In Java, what is the purpose of access modifiers?
To specify the declared accessibility of classes or members
To define new classes
To restrict inheritance
To promote code reuse
14
What is the primary difference between value types and reference types in Java?
Value types for arrays, reference types for variables.
Value types store dta in their own memory while referenc types use pointers
Value types aren't always static; reference types aren't always dynamic.
Value types store integers, reference types can store any data type.
15
What does it mean when a method in Java is declared as "static"?
It is an instance method.
It can only be called on specific instances of a class.
It operates on a given instance of a class.
It belongs to the class and is shared by all instances of the class.
16
What is the primary purpose of exception handling in Java?
To simplify resource management
To execute actions that are guaranteed to succeed
To handle unexpected or exceptional situations during program execution
To intentionally cause program failures
17
What's the primary difference between reference types and value types?
Assignment operation
Data sharing
Static behavior
Memory allocation
18
Which of the following is a feature of an abstract class in Java?
It may contain abstract methods and cannot be instantiated directly.
It must be inherited by a single subclass.
It can be instantiated directly.
It cannot contain abstract methods.
19
In Java, what does the keyword "void" in a method header indicate?
The method does not return a value to its caller.
The method is a constructor.
The method is private.
The method returns a value.
20
what happens when an integer variable "num" is copied to another variable "copyNum" via the assign
The two variables share the same memory location.
The two variables become unrelated.
Both variables are assigned a new value.
The original "num" variable is deleted.
21
How are elements in a Java array accessed?
By using method calls
By using object references
By their names
By using computed indexes
22
What is the purpose of the "length" attribute in Java arrays?
To specify the data type of array elements
To allocate memory for the array
To define the total number of elements in an array
To determine the index of the last element
23
In polymorphism, what does it mean when a variable of a superclass can refer to an object of a sub-type subclass
It indicates a type error.
It means the variable is null.
It is not possible in Java.
It demonstrates polymorphic behavior.
24
When assigning a Circle reference variable to another in reference type operations, what occurs?
New object is created
Both reference the same object
Original variable is copied
Variables become static

Object Oriented Programming - Part 2 Flashcards | StudBud