// Java

class twoDimPrac{

int grade;

public twoDimPrac(int i, int j)//notice the constructor takes in the row and column index values

{

this.grade=i*j;

}

public String toString(){

String ret="";

ret=ret+this.grade;

return ret;

}

public static void main(String [] args){

//use a random number generator to generate the number of rows and columns

//the random number generator will generate values between 1 and 20

int range=(20-1)+1;

int min=1;

int rows=(int)(Math.random()*(range)+min);

//declare the 2 dim array

twoDimPrac [][] myArray;

//Task: intantiate the 2 dimensional array

//Task: using a nested for-loop print out all the objects in the array

for (int i = 0; i < myArray.length; i++) {

for (int j = 0; j < myArray[i].length; j++) {

}

}

}

}

---------------------------------------------------------------------------------------

class threeDimPrac{

int grade;

public threeDimPrac(int i, int j, int k)//notice the constructor takes in the dim1, dim 2 and dim 3 index values

{

this.grade=i*j*k;

}

public String toString(){

String ret="";

ret=ret+this.grade;

return ret;

}

public static void main(String [] args){

//use a random number generator to generate the values of dim1, dim2 and dim3

//the random number generator will generate values between 1 and 20

int range=(20-1)+1;

int min=1;

int dim1=(int)(Math.random()*(range)+min);

//declare the 3 dim array

threeDimPrac [][][] myArray;

//Task: intantiate the 3 dim array

//Task: using a nested for-loop print out all the objects in the array

}

}

---------------------------------------------------------------------------------------

public class Persons

{

String firstName;

String lastName;

int age;

static int id;

int currentid;

public Persons(){

this.firstName="John";

this.lastName="Doe";

this.age = 21;

Persons.id++;

this.currentid=id;

}

public Persons(String fName, String lName, int age){

this.firstName=fName;

this.lastName=lName;

this.age=age;

Persons.id++;

this.currentid=id;

}

//accessor methods

public String getFirstName(){

return this.firstName;

}

public String getLastName(){

return this.lastName;

}

public int getAge(){

return this.age;

}

public int getId(){

return this.currentid;

}

public String toString()

{

return "Last name: " + this.getLastName() + " First name: " + this.getFirstName() + " Age: " + this.getAge();

}

}

---------------------------------------------------------------------------------------

import java.util.Scanner;

import java.io.File;

import java.io.IOException;

public class PersonsClient

{

/*Task 1 write a static function printSameAge() that will take the array of Persons objects and the age to search for as parameters*/

public static void main(String[] args)

{

int arrSize = 0;

int lines = 0;

String str ="";

Persons p1;

Persons []people;

try {

File myFile=new File("persons.txt");

Scanner scan=new Scanner(myFile);

while(scan.hasNextLine()){

str=scan.nextLine();

++arrSize;

}

scan.close();

people = new Persons[arrSize];

scan=new Scanner(myFile);

while(scan.hasNextLine()){

str=scan.nextLine();

String []tok=str.split(",");

p1 = new Persons(tok[1], tok[0], Integer.parseInt(tok[2]));

people[lines++] = p1;

}

scan.close();

/*Write the code to prompt the user to provide an age to search for*/

}

catch(IOException ioe){

System.out.println("The file can not be read");

}

}

}

---------------------------------------------------------------------------------------

public class VehicleA

{

private String vehicle_name;

private double velocity;

private double acceleration;

private double distance;

private int time;

private static int vehicleID;

private int currentID;

private double init_v;

private double init_d;

private VehicleType vt;

public VehicleA()

{

vehicle_name=" ";

velocity=0.0;

acceleration=0.0;

time=0;

distance=0.0;

currentID=0;

init_v=0.0;

init_d=0.0;

}

public VehicleA(String name, double a, int t, double initv, double initd)

{

vehicleID++;

currentID=vehicleID;

vehicle_name=name;

acceleration=a;

time=t;

init_v=initv;

init_d=initd;

}

public String getVehicleName()

{

return vehicle_name;

}

public double getVelocity()

{

return velocity;

}

public double getAcceleration()

{

return acceleration;

}

public double getDistance()

{

return distance;

}

public int getTime()

{

return time;

}

public int getVehicleID()

{

return vehicleID;

}

public int getCurrentID()

{

return currentID;

}

public double getInitV()

{

return init_v;

}

public double getInitD()

{

return init_d;

}

public void setInitV(double inv)

{

init_v=inv;

}

public void setInitD(double ind)

{

init_d=ind;

}

public void setTime(int t)

{

time=t;

}

public void setAcceleration(double acc)

{

acceleration=acc;

}

public void setDistance(double dist)

{

distance=dist;

}

public String toString()

{

String str="The vehicle ID is:"+" "+currentID+" "+"The name of the vehicle is:"+" "+vehicle_name+" "+

"The initial velocity is"+" "+init_v+" "+"The initial distance is"+" "+init_d+" "+"The final velocity is:"+" "+velocity+"m/sec"+" "+"The final distance is:"+" "+distance+"m";

return str;

}

public void calculateV()

{

this.velocity=acceleration*time+init_v;

}

public void calculateD()

{

double timed=(double)time;

double t=Math.pow(timed, 2.0);

this.distance=0.5*acceleration*t+init_v*time+init_d;

}

public String licensePlate()

{

String substr=vehicle_name.substring(3);

String strid=String.valueOf(currentID);

String substr1=substr+strid;

return substr1;

}

public void setVehicleType(VehicleType vehty)

{

this.vt=vehty;

}

public VehicleType getVehicleType()

{

return vt;

}

public boolean equals(Object o)

{

// if o is not an Auto object, return false

if ( ! ( o instanceof VehicleA ) )

return false;

else

{

// type cast o to an Auto object

VehicleA objVeh = ( VehicleA) o;

if (this.init_v==objVeh.init_v&&this.init_d==objVeh.init_d&&this.vt.equals(objVeh.vt)&&this.time==objVeh.time)

return true;

else

return false;

}

}

public void setCalcutedTime(double dist, double acc,double iv)

{

int t=0;

double d=dist;

double a=acc;

double inve=iv;

t=(int)(((Math.pow(inve,2)+Math.sqrt(Math.pow(inve,2)+2*a*d-2*a*init_d))/a));

time=t;

}

}

---------------------------------------------------------------------------------------

public enum VehicleType {FOUR_DOOR_SEDAN,TWO_DOOR_SEDAN, TRUCK, SUV, SPORT, VAN, MINI_VAN };

---------------------------------------------------------------------------------------

import java.util.*;

public class UseVectors

{

public static void main(String[] args)

{

Vector v=new Vector();

VehicleA car1=new VehicleA();

VehicleA car2=new VehicleA();

v.addElement(car1);

v.addElement(car2);

System.out.println("The first object out of the vector:"+" "+v.get(0).toString());

Object o1=v.elementAt(0);

VehicleA veh1=(VehicleA)o1;

veh1.setAcceleration(2);

veh1.setInitD(5.0);

veh1.setInitV(2.0);

veh1.setTime(1);

veh1.calculateV();

veh1.calculateD();

System.out.println("The first object at index 0 out of the vector after we set its initial distance and initial velocity"+" "+v.get(0).toString());

VehicleA v1=(VehicleA)v.get(1);

v1.setAcceleration(3.0);

v1.setTime(2);

v1.calculateV();

v1.calculateD();

System.out.println("The second object at index 1 out of the vector after we set its initial distance and initial velocity"+" "+v.get(1).toString());

//Now lat us exchage positions of teh two objects within teh vector

v.set(0,v1);

v.set(1,veh1);

// Add a new object in the vector index 2

v.addElement(new VehicleA());

//iterate throughteh vector

for (int j=0; j

{

System.out.println("Object at index"+" "+j+"is"+" "+v.get(j).toString());

}

//task1: Add an object v2 of VehicleA whose initial velocity is 2, initial distance is 6 acceleration is 3 and time is 2.

//task2: Add an object v3 of VehicleA whose initial velocity is 3, initial distance is 7 acceleration is 4 and time is 3.

//task3: For object v3, calculate the velocity and the distance.

//task4: Enter the new objects v2 and v3 in the vector.

//task5: Iterate through the vector and display the values of the attributes of each of the 5 objects in the vector.

//task6: Remove the object at index 2 of the vector.

//task7: Display the size of the vector now (v.size())

//task8: Clear the contents of the vector.

//task9: Display the size of the vector again.

}

}