Chapter 4

Question 1

What is use of constructor

Answer 1

For object initialization

Question 2

What are access modifiers

Answer 2

Public (accessible from everywhere)
Private (accessible within a class)
Protected (accessible class and sub classes)
Package access (by default : accessible within current directory)

Question 3

What is setter

Answer 3

It is a function that assign value to any variable. It helps in validation.

Question 4

What about constructors

Answer 4

Constructors are public and they do not have any return type.

Question 5

Does we define destructor in Java

Answer 5

No

Question 6

What is the only way in Java to make object

Answer 6

new operator

Question 7

Do we use -> operator in java

Answer 7

No

Question 8

What are static variable

Answer 8

It is such variable which does not belong to object, but it belongs to class. Unlike instance variable belongs to object.

Question 9

Does non-static member can be called from static

Answer 9

No

Question 10

Is memory management in java automatic

Answer 10

Yes

Question 11

Does java use garbage collection and what is its role

Answer 11

Yes. Garbage collection is for memory management

Question 12

What is command of garbage collection

Answer 12

system.gc

Question 13

What finalize do

Answer 13

It do works as we do in destructor

Question 14

Which is the main class of java and by which every class is inherited

Answer 14

Object class

Question 15

What toString method do

Answer 15

It converts any object state into string and return