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Arrays

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In computer programming, an array is a collection of similar types of data. For example, if we want to store the names of 100 people then we can create an array of the string type that can store 100 names. String[] array = new String[ 100 ]; The number of values in the Java array is fixed. That is, the above array can not store more than 100 elements. How to declare an array in Java? In Java, here is how we can declare an array. dataType[] arrayName; dataType  - it can be  primitive data types  like  int ,  char ,  double ,  byte , etc. or  Java objects arrayName  - it is an  identifier For example, double [] data; Here,  data  is an array that can hold values of type  double . But, how many elements can array this hold? Good question! To define the number of elements that an array can hold, we have to allocate memory for the array in Java. For example, // declare an array double [] data; // allocate memory data = new Double[ 10 ]; Here, the array can store  10  elements. We can a

POLYMORPHISM

package com.cnc ; class Movie { private String name ; public Movie ( String name) { this . name = name; } public String script () { return "The plot is here" ; } public String getName () { return name ; } } class Jollywood extends Movie { public Jollywood () { super ( "Assamese" ); } public String script () { return "jai aai Axom" ; } } class JatinBora extends Jollywood { public JatinBora (){ } public String script () { return "ratnakar" ; } } class Bollywood extends Movie { public Bollywood () { super ( "Hindi" ); } public String script (){ return "Jai hind!" ; } } class Sharukh extends Bollywood { public Sharukh (){ } public String script () { return "hehe" ; } } public class Main { public static void main ( String [] args) { for ( int i= 1 ; i&l

ENCAPSULATION CHALLENGE

package com.cnc ; public class Main { public static void main ( String [] args) { Printer printer = new Printer( 50 , true ); System . out .println( "Initial Page count is " + printer .getNumberOfPages()); int pagesPrinted = printer .getNumberOfPages( 4 ); } } package com.cnc ; public class Printer { private int tonerLevel = 100 ; private int numberOfPages ; private boolean isDuplex ; public Printer ( int tonerLevel, boolean isDuplex) { if (tonerLevel>=- 1 && tonerLevel<= 100 ) { this . tonerLevel = tonerLevel; } else { this . tonerLevel =- 1 ; } this . isDuplex = isDuplex; this . numberOfPages = 0 ; } public int addToner ( int tonerAmount){ if (tonerAmount> 0 && tonerAmount<= 100 ){ if ( this . tonerLevel +tonerAmount > 100 ){ return - 1 ; } this . tonerLevel += tonerAmount

ENCAPSULATION

Consider an address: let's say it has a number and street name only Java  code for this could be : String number = "52" ; String street = "The Leeway" ;   System . out . println ( number + " " + street ); Ok so we see all the variables and the means to which the street was printed to us, if we  encapsulate  though we can do this: public class Address { private String streetName ; private String number ;   public Address ( String streetNametName , String number ){ this . streetName = streetNametName ; this . number = number ; }   public String getStreetName () { return streetName ; }   public void setStreetName ( String streetName ) { this . streetName = streetName ; }   public String getNumber () { return number ; }   public void setNumber ( String number ) { this . number = number ; }   public String fullDescrip