CODEWITHSUNDEEP
javaarraysfor-loopdo-while
Doha Kik
Doha Kik

Reputation: 109

arrays program in java

I am supposed to write a program that could accept user input of aircraft name, destination, number of passengers and flight time. The user is asked if how many aircrafts he/she would like to process. I know that I should make use of arrays. Here's my current codes but it stops after the input of the first aircraft name.

here's what's happening:

Enter airline company: French Air Enter number of aircrafts to process: 3 Enter aircraft name: ABC Enter destination: Tokyo Enter number of passengers: 156 Enter flight time: 10:15 Enter aircraft name: DEF Enter destination: Chile Enter number of passengers: 88 Enter flight time: 11:00 Enter aircraft name: FGH Enter destination: Miami Enter number of passengers: 157 Enter flight time: 12:00

Today's report of international fligts forFrenchAir

AIRCRAFTS DESTINATION NUMBER OF PASSENGERS FLIGHT TIME ABC Tokyo 156 10:15 DEF Chile 88 11:00 FGH Miami 157 12:00

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 4 at AircraftsReport.main(AircraftsReport.java:54)

Here my current codes:

import java.util.*;

public class AircraftsReport 
{
    public static void main(String[] args)
    {
            Scanner input = new Scanner(System.in);

        String airline = "";
        String strAircraft = "", strDestination = "", strFlightTime = "";
        int passengersCount = 0, num2process = 0, ctr = 0, ctr2 = 0;

            System.out.print("Enter airline company: ");
        airline = input.nextLine();

        System.out.print("Enter number of aircrafts to process: ");
        num2process = input.nextInt();

        String[] AIRCRAFTS = new String[num2process];
        String[] DESTINATIONS = new String[num2process];
        String[] FLIGHT_TIME = new String[num2process];
            int[] PASSENGERS_COUNT = new int[num2process];

        while(ctr < num2process)
        {
            System.out.print("Enter aircraft name: ");
            strAircraft = input.next();
            AIRCRAFTS[ctr] = strAircraft;

            System.out.print("Enter destination: ");
            strDestination = input.next();
            DESTINATIONS[ctr] = strDestination;

            System.out.print("Enter number of passengers: ");
            passengersCount = input.nextInt();
            PASSENGERS_COUNT[ctr] = passengersCount;

            System.out.print("Enter flight time: ");
            strFlightTime = input.next();
            FLIGHT_TIME[ctr] = strFlightTime;

            ctr++;

        }


        System.out.println("Today's report of international fligts for" +
                        airline);

        System.out.println("\nAIRCRAFTS\tDESTINATION\tNUMBER OF PASSENGERS" +
                "\tFLIGHT TIME");

        for(ctr2 = 0; ctr2 <= AIRCRAFTS.length; ctr2++)
        {
            System.out.print(AIRCRAFTS[ctr2] + "\t" + DESTINATIONS[ctr2] + 
                    "\t" + PASSENGERS_COUNT[ctr2] + "\t" + FLIGHT_TIME[ctr2]);
            System.out.println();

        }

    }

}

Please help with figuring out what's wrong

It produces the output together with the Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 4 at AircraftsReport.main(AircraftsReport.java:54)

Upvotes: 0

Views: 1460

Answers (5)

duffymo
duffymo

Reputation: 308763

I'd recommend an Aircraft object instead of separate lists of all those items. Java's an object-oriented language. It's better to encapsulate related attributes into a single class and use that.

public class Aircraft {
    private String aircraft;
    private String destination;
    private Date departureTime; 
    private int maxPassengers;

    // You add the rest.
}

// and this in your main    
public Aircraft [] aircrafts = new Aircraft[numAircraft];

But if that's too advanced for you, I'd recommend learning how to read exceptions: 

java.lang.ArrayIndexOutOfBoundsException: 4 at AircraftsReport.main(AircraftsReport.java:54)

Open AircraftsReport.java in a text editor and turn on line number display. Go to line 54 - that's where your error is.

This code works. I'd recommend studying it to see why:

import java.util.Scanner;


/**
 * AircraftsReport description here
 * @author Michael
 * @link http://stackoverflow.com/questions/13900443/arrays-program-in-java/13900477#comment19154335_13900477
 * @since 12/16/12 6:33 AM
 */
public class AircraftsReport {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        String airline = "";
        String strAircraft = "", strDestination = "", strFlightTime = "";
        int passengersCount = 0, num2process = 0, ctr2 = 0;

        System.out.print("Enter airline company: ");
        airline = input.nextLine();

        System.out.print("Enter number of aircrafts to process: ");
        num2process = input.nextInt();

        String[] AIRCRAFTS = new String[num2process];
        String[] DESTINATIONS = new String[num2process];
        String[] FLIGHT_TIME = new String[num2process];
        int[] PASSENGERS_COUNT = new int[num2process];

        // changed this
        for (int ctr = 0; ctr < num2process; ++ctr) {
            System.out.print("Enter aircraft name: ");
            strAircraft = input.next();
            AIRCRAFTS[ctr] = strAircraft;

            System.out.print("Enter destination: ");
            strDestination = input.next();
            DESTINATIONS[ctr] = strDestination;

            System.out.print("Enter number of passengers: ");
            passengersCount = input.nextInt();
            PASSENGERS_COUNT[ctr] = passengersCount;

            System.out.print("Enter flight time: ");
            strFlightTime = input.next();
            FLIGHT_TIME[ctr] = strFlightTime;
        }


        System.out.println("Today's report of international fligts for"+
                airline);

        System.out.println("\nAIRCRAFTS\tDESTINATION\tNUMBER OF PASSENGERS"+
                "\tFLIGHT TIME");

        // changed this
        for (ctr2 = 0; ctr2 < AIRCRAFTS.length; ctr2++) {
            System.out.print(AIRCRAFTS[ctr2]+"\t"+DESTINATIONS[ctr2]+
                    "\t"+PASSENGERS_COUNT[ctr2]+"\t"+FLIGHT_TIME[ctr2]);
            System.out.println();

        }

    }

}

Upvotes: 2

user1832787
user1832787

Reputation: 69

Well first dont initilize your arrays until you know how many num2process should be. Just looking at that your arrays are a size 0. Ask the num2process and then do your arrays. That will probably fix your problem. Because the loop is going through once and getting 0 back (because you initilized the arrays with 0 before you asked)

Upvotes: 0

Harry47
Harry47

Reputation: 101

The Problem with your code is that you are initializing a zero sized array and then asking the user to input num2process. this might do the trick

        System.out.print("Enter airline company: ");
        airline = input.nextLine();

        System.out.print("Enter number of aircrafts to process: ");
        num2process = input.nextInt();
         // Then initialize your arrays


        String[] AIRCRAFTS = new String[num2process];
        String[] DESTINATIONS = new String[num2process];
        String[] FLIGHT_TIME = new String[num2process];
            int[] PASSENGERS_COUNT = new int[num2process];

Upvotes: 0

Sumit Trehan
Sumit Trehan

Reputation: 4035

You are initialsing the value of num2process after you have defined the arrays. The size of the arrays is 0. Modify the code like this.

System.out.print("Enter airline company: ");
airline = input.nextLine();

System.out.print("Enter number of aircrafts to process: ");
num2process = input.nextInt();

String[] AIRCRAFTS = new String[num2process];
String[] DESTINATIONS = new String[num2process];
String[] FLIGHT_TIME = new String[num2process];
int[] PASSENGERS_COUNT = new int[num2process];

Upvotes: 0

jlordo
jlordo

Reputation: 37813

In this line 

int passengersCount = 0, num2process = 0, ctr = 0, ctr2 = 0;

you declare num2process as 0.

So the next line

String[] AIRCRAFTS = new String[num2process];

creates an array of 0 length.

A few lines after that you reassign num2process:

num2process = input.nextInt();

but this won't change the size of the previously created array.

You enter the do while loop once (because they always get executed at least once), and the condition check subsequently fails

} while(ctr < AIRCRAFTS.length);

because ctr is 1 at this point (after executing ctr++;) and AIRCRAFTS.length is still 0.

Upvotes: 2

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