How to aggregate values stored inside an array in java

Question

I am creating a simple games score report generator program which takes input and turns it into a .txt file. It takes a name, a game name, an achievement score and minutes played and I want to be able to tally up the amount of games input, add up the achievement score and also add up the minutes (and convert to hours).

This is an example of how my output to .txt looks at the moment -

This is an example of how I would like an output to look -

How do I aggregate data that was input into the console and stored in an array to get results that I want?

PrintWriter writer = new PrintWriter(new FileOutputStream("Gaming Report Data", true));
writer.println("Player : " + gamerName);
writer.println();
writer.println("--------------------------------");
writer.println();
String[] report = gamerReport.split(":");
writer.println("Game: " + report[0] + ", score= " +report[1] + ", minutes played= " +report[2]);
writer.println();
writer.close();

Source code

package JavaProject;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Scanner;
import java.nio.file.*;



public class JavaProject {

    private static final int minutesPlayed = 0;
    private static char[] input;

    public static void main(String[] args) {


        //variables 
        int hrs = minutesPlayed * 60;
        int mins;   
        String gamerName, gamerReport = null;
        int gameCount;
        int errorCount;


        //Main data storage arrays
        String[] gameNames = new String[100];
        int[] highScores = new int[100];
        int[] minutesPlayed = new int [100];

        @SuppressWarnings("resource")
        Scanner Scan = new Scanner(System.in);

        //formatting for output and input
        System.out.println("////// Game Score Report Generator \\\\\\\\\\\\");
        System.out.println("     ");

        //User enters either their name or quit. Entering a name will move on to next part
        for ( ; ; )
        {
            System.out.print("Enter your Name.");
            System.out.println("   ");
            gamerName = Scan.nextLine();


            for(int b = 1; b < 99; b++ ) { //this is making the code loop 100 times




        //user is given an example of input format 
        System.out.println("    ");
        System.out.println("Input Gamer Information " + "Using Format --> Game : Achievement Score : Minutes Played");
        System.out.println("FALSE DATA FORMAT WILL CAUSE ERROR");
        System.out.println("    ");

        //another data input guide which is just above where data input is in console
        System.out.println("Game : Achievement Score : Minutes Played");
        gamerReport = Scan.nextLine();

        String[] splitUpReport; // an array of string


        if (gamerReport.equalsIgnoreCase("quit")) {
            System.out.println("You have quit!");
            return;
        }
        splitUpReport = gamerReport.split(":");


        int i = 0;

        //copy data from split text into main data storage arrays 
        gameNames[i] = splitUpReport[0];
        highScores[i] = Integer.parseInt(splitUpReport[1].trim() );
        minutesPlayed[i] = Integer.parseInt(splitUpReport[2].trim());




        //output to file using a PrintWriter using a FileOutPutStream with append set to true within the printwriter constructor
        //

        try
        {

            PrintWriter writer = new PrintWriter(new FileOutputStream("Gaming Report Data", true));
            writer.println("Player : " + gamerName);
            writer.println();
            writer.println("--------------------------------");
            writer.println();
            String[] report = gamerReport.split(":");
            writer.println("Game: " + report[0] + ", score= " +report[1] + ", minutes played= " +report[2]);
            //writer.println("Games Played : " + minutesPlayed);
            writer.close();





        } catch (IOException e)
        {
            System.err.println("You have made an error with data input");
        }

        }
        System.out.println("You have quit!");
            }



    }




    public static char[] getInput() {
        return input;
    }

    public static void setInput(char[] input) {
        JavaProject.input = input;
    }

}

Answer 1

Suggestion:

Create a model of the data as a new simple class:

public class GameReportModel{
   String gamename = null;
   String username = null;
   int score = 0;
   int minutesplayed = 0;
}

Now you can use an ArrayList of this model to store data before generate the report:

//Declare
ArrayList<GameReportModel> myArray = new ArrayList<GameReportModel>();

//Populate (example) for each input

GameReportModel myobj = new GameReportModel();

myobj.gamename = "My Game"; //<<from input source
myobj.username = "John";    //<<from input source
myobj.score = 20;           //<<from input source
myobj.minutesplayed = 45;   //<<from input source

myArray.add(myobj);

// Iterate

for(GameReportModel line : myArray){
   writer.println("Player : " + line.username);
   ... and sumarize for each Player

}

Now you can build some scripts to sort by name, game. This method turn it easy but consume more virtual machine resources (memory and steps). But you can manipulate data with another perspective.

Add and remove Array elements easy.

Answer 2

So I am assuming that your array data structure looks like this:

Object[] report = new Object[] {new String(), new Integer(), new Integer()} 

where the first entry is the game name, the second is the score, and the third is the time played.

I would suggest that you bundle this data into its own object instead of tracking every 3 positions in an array. Try:

public class Game 
{ 

    private String name; public String getName() { return name; }
    private int score; public int getScore() { return score; }
    private int minutesPlayed; public int getMinutesPlayed() { return minutesPlayed; } 

    public Game(String name, int score, int minutesPlayed)
    {
        this.name = name;
        this.score = score;
        this.minutesPlayed = minutesPlayed
    }

    @Override
    public String toString()
    {
        return "Game: " + name + ", score= " + score + ", minutes played= " + minutesPlayed);
    }
}

You can then use this object to represent game data and hold and array of these objects like this:

Game[] games = new Game[]{
    new Game("Game 1", 52, 89),
    new Game("Game 2", 57, 58),
    new Game("Game 3", 67, 86)
};

This array allows us to access each game as a single entity; for example games[0] would get the reference to the 1st game object in the array. These games can have their data accessed by calling the "getters" for the 3 fields contained in the Game object. games[0].getName() would return the name for the first Game object; likewise, games[0].getMinutesPlayed() would return the minutes played for the first game.

Since we overrode the toString method offered to all classes from java's object class to output a string of the data desired in the way your first file I/O was structured. You can call writer.println(games[i]) where i is and index in your array of games to write the data for a individual game.

To concatenate this data into the output you desired. We can do the following: // get the number of games played int gamesPlayed = games.length;

// get the raw data on score and time
int totalScore = 0;
int totalMinutesPlayed = 0;
for(int i = 0; i < games.length; i++)
{
    totalScore += games[i].getScore();
    totalMinutesPlayed += games[i].getMinutesPlayed;
}

// compile the output string
String output = "Games Played: " + gamesPlayed
 + "\n\nTotal Achievement: " + totalScore
 + "\n\nTotal Time: " + totalMinutesPlayed
 + " (" + totalMinutesPlayed / 60
 + " hours and " + totalMinutesPlayed % 60
 + " minutes).";

// write the string to the file
writer.println(output);