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5 222.0 true

As you can see, the values contained in the instance variables named myInt and myBoolean are the values of 5 and true placed there by the constructor, based on incoming parameter values. The value in the instance variable named myDouble is the value placed there by the initialization expression when the variable was declared.

Default initialization

If you don't take any steps to initialize instance variables, they will be automatically initialized. Numeric instance variables will be initialized withzero value for the type of variable involved. Instance variables of type boolean will be initialized to false. Instance variables of type char will be initialized to a Unicode value with all 16 bits set to zero. Reference variableswill be initialized to null.

Initialization expression

If you provide an initialization expression for an instance variable, the value of the expression will overwrite the default value, and the value of theinitialization expression will become the initial value for the instance variable.

Assignment in constructor code

If you use an assignment statement in a constructor to assign a value to an instance variable, that value will overwrite the value previously placed in theinstance variable either by default, or by use of an initialization expression. The constructor has the "last word" on the matter of initialization of instancevariables.

Back to Question 10

Answer 9

A. Compiler Error

Explanation 9

The default constructor

When you define a class, you are not required to define a constructor for the class. If you do not define a constructor for the class, a default constructorthat takes no arguments will be provided on your behalf. You can instantiate new objects of the class by applying the new operator to the default constructor asshown in the following code fragment from Question 8 .

new Worker().display();

Behavior of the default constructor

As illustrated in Question 8 , when you don't provide a constructor that purposely initializes the values of instance variables, or initialize them insome other manner, they will automatically be initialized to the default values described in Question 8 .

Defining overloaded constructors

You can also define one or more overloaded constructors having different formal argument lists. The typical intended purpose of such constructors is touse incoming parameter values to initialize the values of instance variables in the new object.

A parameterized constructor

This is illustrated in the following code fragment. This fragment receives two incoming parameters and uses the values of those two parameters toinitialize the values of two instance variables belonging to the new object.

class Worker{ private int myInt;private boolean myBoolean; public Worker(int x, boolean y){myInt = x; myBoolean = y;}//end parameterized constructor//display() omitted for brevity}// end class Worker

If you define any constructors ...

However, there is a pitfall that you must never forget.

If you define any constructors in your new class, you must define all constructors that will ever be required for your new class.

Questions & Answers

how does Neisseria cause meningitis
Nyibol Reply
what is microbiologist
Muhammad Reply
what is errata
Muhammad
is the branch of biology that deals with the study of microorganisms.
Ntefuni Reply
What is microbiology
Mercy Reply
studies of microbes
Louisiaste
when we takee the specimen which lumbar,spin,
Ziyad Reply
How bacteria create energy to survive?
Muhamad Reply
Bacteria doesn't produce energy they are dependent upon their substrate in case of lack of nutrients they are able to make spores which helps them to sustain in harsh environments
_Adnan
But not all bacteria make spores, l mean Eukaryotic cells have Mitochondria which acts as powerhouse for them, since bacteria don't have it, what is the substitution for it?
Muhamad
they make spores
Louisiaste
what is sporadic nd endemic, epidemic
Aminu Reply
the significance of food webs for disease transmission
Abreham
food webs brings about an infection as an individual depends on number of diseased foods or carriers dully.
Mark
explain assimilatory nitrate reduction
Esinniobiwa Reply
Assimilatory nitrate reduction is a process that occurs in some microorganisms, such as bacteria and archaea, in which nitrate (NO3-) is reduced to nitrite (NO2-), and then further reduced to ammonia (NH3).
Elkana
This process is called assimilatory nitrate reduction because the nitrogen that is produced is incorporated in the cells of microorganisms where it can be used in the synthesis of amino acids and other nitrogen products
Elkana
Examples of thermophilic organisms
Shu Reply
Give Examples of thermophilic organisms
Shu
advantages of normal Flora to the host
Micheal Reply
Prevent foreign microbes to the host
Abubakar
they provide healthier benefits to their hosts
ayesha
They are friends to host only when Host immune system is strong and become enemies when the host immune system is weakened . very bad relationship!
Mark
what is cell
faisal Reply
cell is the smallest unit of life
Fauziya
cell is the smallest unit of life
Akanni
ok
Innocent
cell is the structural and functional unit of life
Hasan
is the fundamental units of Life
Musa
what are emergency diseases
Micheal Reply
There are nothing like emergency disease but there are some common medical emergency which can occur simultaneously like Bleeding,heart attack,Breathing difficulties,severe pain heart stock.Hope you will get my point .Have a nice day ❣️
_Adnan
define infection ,prevention and control
Innocent
I think infection prevention and control is the avoidance of all things we do that gives out break of infections and promotion of health practices that promote life
Lubega
Heyy Lubega hussein where are u from?
_Adnan
en français
Adama
which site have a normal flora
ESTHER Reply
Many sites of the body have it Skin Nasal cavity Oral cavity Gastro intestinal tract
Safaa
skin
Asiina
skin,Oral,Nasal,GIt
Sadik
How can Commensal can Bacteria change into pathogen?
Sadik
How can Commensal Bacteria change into pathogen?
Sadik
all
Tesfaye
by fussion
Asiina
what are the advantages of normal Flora to the host
Micheal
what are the ways of control and prevention of nosocomial infection in the hospital
Micheal
what is inflammation
Shelly Reply
part of a tissue or an organ being wounded or bruised.
Wilfred
what term is used to name and classify microorganisms?
Micheal Reply
Binomial nomenclature
adeolu
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Source:  OpenStax, Object-oriented programming (oop) with java. OpenStax CNX. Jun 29, 2016 Download for free at https://legacy.cnx.org/content/col11441/1.201
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