Java Programming Examples - Ticket Booking, Printing, Polymorphism, and Static Keywords

**[\*\* FinalVariableExample.java\*\*]** package javaPrjChap1; import java.util.Scanner; /\*\* \* This class is used to understand the use of final keyword with instance and local variables. \* We use the example of a ticket booking window. \*/ public class FinalVariableExample { public fina...

**[\*\* FinalVariableExample.java\*\*]** package javaPrjChap1; import java.util.Scanner; /\*\* \* This class is used to understand the use of final keyword with instance and local variables. \* We use the example of a ticket booking window. \*/ public class FinalVariableExample { public final int TOTAL\_TICKETS; //we can skip initializing final variable here. //or we can use the following syntax which initializes the final variable at the time of declaration // public final int totalTickets=200; public int tktsAvailable=0; /\*\* \* The class constructor is used to initialise the final instance variable, TOTAL\_TICKETS \* \@param totTkc \*/ public FinalVariableExample(int totTkc) { //initialising a final variable. this.TOTAL\_TICKETS = totTkc; } /\*\* \* This method takes the day of the week from the user and sets the no of available tickets for sale on \* that day. \* Monday,Tuesday,Wednesday,Thursday - 150 \* Friday - ALL TICKETS \* Saturday, Sunday - 175 \*/ public void setAvailableTkts(String wkDy) { //Depending on the day of the week, we set the available tickets count. For this we are //using switch case implementation of case list and arrow case as per JDK21 version switch(wkDy) { case \"Mon\",\"Tue\",\"Wed\",\"Thur\"-\> { tktsAvailable = 150; } case \"Fri\"-\> { tktsAvailable = 200; } case \"Sat\",\"Sun\"-\> { tktsAvailable = 175; } default-\> tktsAvailable = 0; } } public boolean bookTickets(final int noOfTkts) { final double TKTPRC =150.50; //assign some ticket price to the local variable. double tktAmount=0.0; //check if the noOfTkts are less than the total tickets. proceed with the booking then. else return false if(noOfTkts \< tktsAvailable) { tktAmount = TKTPRC\*noOfTkts; System.out.println(\"Please pay: \"+tktAmount+\" at the ticket counter.\"); //updating available tickets count. tktsAvailable = tktsAvailable - noOfTkts; } else return false; return true; } public static void main(String arg\[\]) { FinalVariableExample fnVrObj = new FinalVariableExample(120); fnVrObj.setAvailableTkts(\"Mon\"); System.out.println(\"Available tickets are:\"+ fnVrObj.tktsAvailable); if(fnVrObj.bookTickets(100)) System.out.println(\"Tickets are booked!! Please pay the amount\"); else System.out.println(\"Tickets could not be booked. Better luck next time\"); System.out.println(\"Available tickets are:\"+ fnVrObj.tktsAvailable); if(fnVrObj.bookTickets(70)) System.out.println(\"Tickets are booked!! Please pay the amount\"); else System.out.println(\"Tickets could not be booked. Better luck next time\"); } } **[\*\*Printer.java\*\*\ ]**\ package javaPrjChap1; import java.util.Scanner; public class Printer { String model; String location; String choice; public void print() { System.out.println(\"I will print all the pages in black and white\"); } public void print(boolean flag) { System.out.println(\"I will print all the pages in colours!!\"); } public void printChoice() { System.out.println(\"Hello user! Enter Yes/yes if you want a colour print. Else enter No/no\"); Scanner sc = new Scanner(System.in); choice = sc.next(); if(choice.equalsIgnoreCase(\"Yes\")) { //call print() for colour copies print(true); } else if(choice.equalsIgnoreCase(\"No\")) { //call print for black and white print(); } else System.out.println(\"You have entered some incorrect input choice.\"); } } **[\*\*PolymorphismDemo.java\*\*]** package pkgPolymorphism; import java.util.\*; public class PolymorphismDemo { public static void main(String ar\[\]) { String chc; //create object of printer class Printer prtntObj = new Printer(); System.out.println(\"Enter YES if you want a colour print else enter NO\"); Scanner sc = new Scanner(System.in); chc = sc.next(); if(chc.equalsIgnoreCase(\"YES\")) { //this is when the user wants a colour print prtntObj.printPaper(true); } else if(chc.equalsIgnoreCase(\"NO\")) { //thisis when the user wants a black and white print prtntObj.printPaper(); } else System.out.println(\"Your input does not match\"); } }//end of class **[\*\*StaticExample.java\*\*]** package chap1; import java.util.Scanner; /\*\* \* This class is used to understand the working of static keyword with a variable using multiple ticket \* booking windows scenario \*/ public class StaticExample { public final int TOTAL\_TICKETS = 200; public int tktsAvailable=0; /\*\* \* This method takes the day of the week from the user and sets the no of available tickets for sale on \* that day. \* Monday,Tuesday,Wednesday,Thursday - 150 \* Friday - ALL TICKETS \* Saturday, Sunday - 175 \*/ public void setAvailableTkts(String wkDy) { //Depending on the day of the week, we set the available tickets count. For this we are //using switch case implementation of case list and arrow case as per JDK21 version switch(wkDy) { case \"Mon\",\"Tue\",\"Wed\",\"Thur\"-\> { tktsAvailable = 150; } case \"Fri\"-\> { tktsAvailable = 200; } case \"Sat\",\"Sun\"-\> { tktsAvailable = 175; } default-\> tktsAvailable = 0; } } public boolean bookTickets(final int noOfTkts) { final double TKTPRC =150.50; //assign some ticket price to the local variable. double tktAmount=0.0; //check if the noOfTkts are less than the total tickets. proceed with the booking then. else return false if(noOfTkts \< tktsAvailable) { tktAmount = TKTPRC\*noOfTkts; System.out.println(\"Please pay: \"+tktAmount+\" at the ticket counter.\"); //updating available tickets count. tktsAvailable = tktsAvailable - noOfTkts; } else return false; return true; } public static void main(String ar\[\]) { StaticExample stExObj1 = new StaticExample(); StaticExample stExObj2 = new StaticExample(); StaticExample stExObj3 = new StaticExample(); stExObj1.setAvailableTkts(\"Mon\"); stExObj2.setAvailableTkts(\"Mon\"); stExObj3.setAvailableTkts(\"Mon\"); //invoke booking method on all the three objects. print the total tickets System.out.println(\"Available tickets are:\"+ stExObj1.tktsAvailable); if(stExObj1.bookTickets(100)) System.out.println(\"Tickets are booked!! Please pay the amount\"); else System.out.println(\"Tickets could not be booked. Better luck next time\"); System.out.println(\"Available tickets are:\"+ stExObj1.tktsAvailable); System.out.println(\"Available tickets are:\"+ stExObj2.tktsAvailable); if(stExObj2.bookTickets(100)) System.out.println(\"Tickets are booked!! Please pay the amount\"); else System.out.println(\"Tickets could not be booked. Better luck next time\"); System.out.println(\"Available tickets are:\"+ stExObj2.tktsAvailable); System.out.println(\"Available tickets are:\"+ stExObj3.tktsAvailable); if(stExObj3.bookTickets(100)) System.out.println(\"Tickets are booked!! Please pay the amount\"); else System.out.println(\"Tickets could not be booked. Better luck next time\"); System.out.println(\"Available tickets are:\"+ stExObj3.tktsAvailable); } } **[\*\*ThisExample.java\*\*]** package javaPrjChap1; public class ThisExample { int i,j; public ThisExample() { this(0,0); //i=0; //j=0; } public ThisExample(int val) { this(val,val); //i=j=val; } public ThisExample(int v1,int v2) { i=v1; j=v2; } public void showValues(){ this.showValues(\"both\"); } public void showValues(String s) { System.out.println(\"i is\...\"+i); System.out.println(\"j is\...\"+j); } public static void main(String arg\[\]) { ThisExample thsExObj = new ThisExample(); //ThisExample thsExObj1 = new ThisExample(10); //ThisExample thsExObj2 = new ThisExample(12,13); thsExObj.showValues(); //thsExObj1.showValues(); //thsExObj2.showValues(); } }