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How to format multiplication table into 4 rows and columns respectively and test for even number multiplication table between 1 and 9?

This is the code I atempted with the guide of external video which didnt cover expected output in terms of formatting
public class Lab3Class {
public static void main(String[] args) {
// TODO Auto-generated method stub
int table = 1;
while(table<10) {
int i = 1;
while(i<=10)
{
System.out.println(table+ " * "+i+" = "+(table*i));
i++;
}
System.out.println(" ");
table++;
}
}
}

You are just missing a check for even numbers i.e. if (table % 2 == 0).
public class Main {
public static void main(String[] args) {
int table = 1;
while (table < 10) {
if (table % 2 == 0) {
int i = 1;
while (i <= 10) {
System.out.println(table + " * " + i + " = " + (table * i));
i++;
}
}
System.out.println();
table++;
}
}
}
Alternatively, you can start table with 2 and increment it by 2 in each iteration as follows:
public class Main {
public static void main(String[] args) {
int table = 2;
while (table < 10) {
int i = 1;
while (i <= 10) {
System.out.println(table + " * " + i + " = " + (table * i));
i++;
}
System.out.println();
table += 2;
}
}
}
If you need to print it in a tabular structure, you can write the loops as follows:
public class Main {
public static void main(String[] args) {
for (int line = 1; line <= 10; line++) {
for (int i = 2; i <= 10; i += 2) {
System.out.print(i + "*" + line + "=" + (i * line) + "\t");
}
System.out.println();
}
}
}
Output:
2*1=2 4*1=4 6*1=6 8*1=8 10*1=10
2*2=4 4*2=8 6*2=12 8*2=16 10*2=20
2*3=6 4*3=12 6*3=18 8*3=24 10*3=30
2*4=8 4*4=16 6*4=24 8*4=32 10*4=40
2*5=10 4*5=20 6*5=30 8*5=40 10*5=50
2*6=12 4*6=24 6*6=36 8*6=48 10*6=60
2*7=14 4*7=28 6*7=42 8*7=56 10*7=70
2*8=16 4*8=32 6*8=48 8*8=64 10*8=80
2*9=18 4*9=36 6*9=54 8*9=72 10*9=90
2*10=20 4*10=40 6*10=60 8*10=80 10*10=100
As you can see, it looks cleaner by using a for loop. However, I recommend you also practice it with a while loop. Once you gain more confidence, I also recommend you use String::format or System.out.printf for better formatting.
This is a very small data set but if the dataset is huge, you can improve the performance by reducing the I/O operation. For this, you can append the result to a StringBuilder and print it just once at the end.
public class Main {
public static void main(String[] args) {
StringBuilder sb = new StringBuilder();
for (int line = 1; line <= 10; line++) {
for (int i = 2; i <= 10; i += 2) {
sb.append(i).append('*').append(line).append('=').append(i * line).append('\t');
}
sb.append('\n');
}
System.out.println(sb);
}
}

How do I print this 2 D array next to the appropriate row?

//Game Summary
System.out.println("Game Summary");
System.out.println("------------");
System.out.print(teams[0] + ":");
for (int i = 0; i < scores.length; i++) {
for (int j = 0; j < scores[i].length; j++) {
System.out.printf("%3d", scores[i][j]);
}
System.out.println();;
System.out.print(teams[1] +":");
}
I have a program that asks the user for the scores for each team in a football game and records them in a double array, scores[][], and another array that stores the team names, teams[]. There is another method below that adds the scores up. When I run the program it prints the team[1] twice. How do I fix this? Example is below
Game Summary
------------
Ravens: 14 21 3 7
Steelers: 0 0 0 0
Steelers:Ravens:45 //(here is the problem, team[1] is printed twice)
Steelers:0

I tried to reproduce your case. As I understand, you want to avoid duplication of teams.
You can try to use this solution:
int[][] scores = {{14, 21, 3, 7}, {0,0,0,0}};
String teams[] = {"Ravens", "Steelers"};
System.out.println("Game Summary");
System.out.println("------------");
for (int i = 0; i < scores.length; i++) {
System.out.print(teams[i] +":");
for (int j = 0; j < scores[i].length; j++) {
System.out.printf("%3d", scores[i][j]);
}
System.out.println();
}
Outputs:
Game Summary
------------
Ravens: 14 21 3 7
Steelers: 0 0 0 0

I would write a little class like this...
private static class FootballTeam
{
private String name;
private ArrayList<Integer> scoreList;
public FootballTeam(String name)
{
this.name = name;
this.scoreList = new ArrayList<>();
}
public FootballTeam(String name, int ... scores)
{
this.name = name;
this.scoreList = new ArrayList<>();
for(int score : scores)
{
this.scoreList.add(score);
}
}
// getter and setter methods ...
#Override public String toString()
{
StringBuilder builder = new StringBuilder();
builder.append(this.name);
for(int score : this.scoreList)
{
builder.append(String.format("%3i", score));
}
return builder.toString();
}
}
Then you can use it like this...
FootballTeam [] teams = new FootballTeam [NumberOfTeams];
// read in scores and store it in the football team objects with the setter methods
System.out.println("Game Summary");
System.out.println("------------");
for(FootballTeam team : teams)
{
System.out.println(team.toString());
}

(Arraylist) Crashes when user defined String input

The purpose of the program is to let the user input 5 numbers and select which game they would like to compare them to (lotto/lottoplus1/lottoplus2) with each having a unique set of 5 numbers, then to be stored in an arraylist.
The national lottery run three draws on each night: Lotto, Lotto plus one and Lotto plus 2.
generate numbers for each of these draws.
When a user enters a line of numbers they should also enter either:"lotto", "plus1", or "plus2" to specify which of the draws their numbers should be compared to.
This value should then be assigned to that specific line of numbers and the numbers on that line should be compared against each set of Lotto numbers as required.
Heres my problem! When I input my five numbers then lets say 'plus1' to assign the comparison of those numbers to lotteryPlusOne it crashes and outputs this message:
Exception in thread "main" java.lang.NullPointerException at lottoapp.lottoCounter.compareNums(lottoCounter.java:136) at lottoapp.LottoApp.main(LottoApp.java:61) C:\Users\x15587907\AppData\Local\NetBeans\Cache\8.1\executor‌​-snippets\run.xml:53‌​: Java returned: 1 BUILD FAILED (total time: 15 seconds)
Below is line 136 it is in the Instantiable class in the public void compareNums() method
l = madeUpArrayList.get(i); <-----
Main App
package lottoapp;
import javax.swing.JOptionPane;
import java.util.ArrayList;
import java.util.Arrays;
public class LottoApp {
public static void main(String[] args) {
//declare vars/objects/arrays
int[] lottery = new int[5]; //5 Winning numbers
int[] lotteryPlus1 = new int[5]; //5 Winning LP1 numbers
int[] lotteryPlus2 = new int[5]; //5 Winning LP2 numbers
String gameType;
int number1;
int number2;
int number3;
int number4;
int number5;
//array list called madeUpArrayList
ArrayList<lottoCounter> madeUpArrayList = new ArrayList();
//object declare and create
lottoCounter myCount = new lottoCounter();
//winNums/getLottery need to be initialised at top of program
myCount.winNums();
lottery = myCount.getLottery();
lotteryPlus1 = myCount.getLotteryPlus1();
lotteryPlus2 = myCount.getLotteryPlus2();
//Displays winning numbers (Testing Purposes)
System.out.println(Arrays.toString(lottery));
System.out.println(Arrays.toString(lotteryPlus1));
System.out.println(Arrays.toString(lotteryPlus2));
//Array List
for (int i = 0; i < 1; i++) {
lottoCounter l = new lottoCounter();
number1 = Integer.parseInt(JOptionPane.showInputDialog(null, "Enter number 1 "));
number2 = Integer.parseInt(JOptionPane.showInputDialog(null, "Enter number 2 "));
number3 = Integer.parseInt(JOptionPane.showInputDialog(null, "Enter number 3 "));
number4 = Integer.parseInt(JOptionPane.showInputDialog(null, "Enter number 4 "));
number5 = Integer.parseInt(JOptionPane.showInputDialog(null, "Enter number 5 "));
gameType = JOptionPane.showInputDialog(null, "Select a game type for comparison ... lotto/plus1/plus2");
l.setNumber1(number1);
l.setNumber2(number2);
l.setNumber3(number3);
l.setNumber4(number4);
l.setNumber5(number5);
l.setGameType(gameType);
madeUpArrayList.add(l);
}
//Comparison
myCount.compareNums();
//Output Lotto,Lotto Plus One and Lotto plus Two correct guesses
JOptionPane.showMessageDialog(null, "Guesses correct for Regular Lottery correct is " + myCount.getCorrectLotto());
JOptionPane.showMessageDialog(null, "Guesses correct for Lottery Plus One is " + myCount.getCorrectPlusOne());
JOptionPane.showMessageDialog(null, "Guesses correct for Lottery Plus Two is " + myCount.getCorrectPlusTwo());
}
}
Instantiable Class
package lottoapp;
import java.util.ArrayList;
public class lottoCounter {
//Variables/Constants/data members
private int correctLotto;
private int correctPlusOne;
private int correctPlusTwo;
private int[] lottery = new int[5];
private int[] lotteryPlus1 = new int[5];
private int[] lotteryPlus2 = new int[5];
private int number1;
private int number2;
private int number3;
private int number4;
private int number5;
private String gameType;
private ArrayList<lottoCounter> madeUpArrayList;
//Constructor
lottoCounter() {
correctLotto = 0;
correctPlusOne = 0;
correctPlusTwo = 0;
number1 = 0;
number2 = 0;
number3 = 0;
number4 = 0;
number5 = 0;
gameType = " ";
}
//setters
public void setCorrectLotto(int correctLotto) {
this.correctLotto = correctLotto;
}
public void setCorrectPlusOne(int correctPlusOne) {
this.correctPlusOne = correctPlusOne;
}
public void setCorrectPlusTwo(int correctPlusTwo) {
this.correctPlusTwo = correctPlusTwo;
}
public void setLottery(int[] lottery) {
this.lottery = lottery;
}
public void setLotteryPlus1(int[] lotteryPlus1) {
this.lotteryPlus1 = lotteryPlus1;
}
public void setLotteryPlus2(int[] lotteryPlus2) {
this.lotteryPlus1 = lotteryPlus2;
}
public void setNumber1(int number1) {
this.number1 = number1;
}
public void setNumber2(int number2) {
this.number2 = number2;
}
public void setNumber3(int number3) {
this.number3 = number3;
}
public void setNumber4(int number4) {
this.number4 = number4;
}
public void setNumber5(int number5) {
this.number5 = number5;
}
public void setGameType(String gameType) {
this.gameType = gameType;
}
public lottoCounter(ArrayList<lottoCounter> madeUpArrayList) {
this.madeUpArrayList = madeUpArrayList;
}
//COMPUTE
//Lottery Generator | random num generator (1-40)Lottery
public void winNums() {
for (int i = 0; i < lottery.length; i++) {//Generating 1 to 40 numbers
lottery[i] = (int) Math.floor(1 + Math.random() * 40);//Using Math.random
for (int j = 0; j < i; j++) {
if (lottery[i] == lottery[j]) {
i--;
}
}
}
//Lottery plus 1 generator
for (int i = 0; i < lotteryPlus1.length; i++) {//Generating 1 to 40 numbers
lotteryPlus1[i] = (int) Math.floor(1 + Math.random() * 40);//Using Math.random
for (int j = 0; j < i; j++) {
if (lotteryPlus1[i] == lotteryPlus1[j]) {
i--;
}
}
}
//Lottery plus 2 generator
for (int i = 0; i < lotteryPlus2.length; i++) {//Generating 1 to 40 numbers
lotteryPlus2[i] = (int) Math.floor(1 + Math.random() * 40);//Using Math.random
for (int j = 0; j < i; j++) {
if (lotteryPlus2[i] == lotteryPlus2[j]) {
i--;
}
}
}
}
//Counter for Lottery/LotteryPlusOne/LotteryPlusTwo (COMPARISON)
public void compareNums() {
for (int i = 0; i < 1; i++) {
for (int j = 0; j < 5; j++) {
lottoCounter l;
l = madeUpArrayList.get(i);
if (l.getGameType().equals("lotto")) {
if (lottery[j] == l.getNumber1() || lottery[j] == l.getNumber2() || lottery[j] == l.getNumber3() || lottery[j] == l.getNumber4() || lottery[j] == l.getNumber5()) {
correctLotto++;
}
}
if (l.getGameType().equals("plus1")) {
if (lotteryPlus1[j] == l.getNumber1() || lotteryPlus1[j] == l.getNumber2() || lotteryPlus1[j] == l.getNumber3() || lotteryPlus1[j] == l.getNumber4() || lotteryPlus1[j] == l.getNumber5()) {
correctPlusOne++;
}
}
if (l.getGameType().equals("plus2")) {
if (lotteryPlus2[j] == l.getNumber1() || lotteryPlus2[j] == l.getNumber2() || lotteryPlus2[j] == l.getNumber3() || lotteryPlus2[j] == l.getNumber4() || lotteryPlus2[j] == l.getNumber5()) {
correctPlusTwo++;
}
}
}
}
}
//getters (return values to App Class)
public int getCorrectLotto() {
return correctLotto;
}
public int getCorrectPlusOne() {
return correctPlusOne;
}
public int getCorrectPlusTwo() {
return correctPlusTwo;
}
public int[] getLottery() {
return lottery;
}
public int[] getLotteryPlus1() {
return lotteryPlus1;
}
public int[] getLotteryPlus2() {
return lotteryPlus2;
}
public int getNumber1() {
return number1;
}
public int getNumber2() {
return number2;
}
public int getNumber3() {
return number3;
}
public int getNumber4() {
return number4;
}
public int getNumber5() {
return number5;
}
public String getGameType() {
return gameType;
}
public ArrayList<lottoCounter> getMadeUpArrayList() {
return madeUpArrayList;
}
}

I am not sure about anyone else but it would be nice to have more info, like the data in the arrays: lottery, lotteryPlus1 and madeUpArrayList ect. Just to make sure that they actually have any data in them because according to your Exception you have a java.lang.NullPointerException in your method compareNums in line 136 of your class. Because you did not post line numbers I am not sure when the exception occurs.
I am assuming one of your arrays does not have any data in it or one or more of your arrays do not have 5 total entries of data in it because your for loop iterates 5 times. But again without seeing how or when your arrays are instantiated I do not think it is possible for anyone to confirm that is the cause of your problems. For example lotteryPlus2[] may only have data for lotteryPlus2[0],lotteryPlus2[1],and lotteryPlus2[2] so when j gets to 3 in the loop lotteryPlus2[3] does not exist and throws a java.lang.NullPointerException.
Also I am curious on why you use this for loop for (int i = 0; i < 1; i++){}
This loop only loops once no matter what so why have it there at all since your main method will always run at least once anyways? Honest question, I am a beginner programmer so you may be using it for something that I have no knowledge about.

n-gram similarity for the words in the file

/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package sim;
import java.io.*;
import java.util.Arrays;
import java.util.Scanner;
import java.util.logging.Level;
import java.util.logging.Logger;
import static jdk.nashorn.internal.objects.NativeMath.max;
/**
*
* #author admin
*/
public class Sim {
public String[][] bigramizedWords = new String[500][100];
public String[] words = new String[500];
public File file1 = new File("file1.txt");
public File file2 = new File("file2.txt");
public int tracker = 0;
public double matches = 0;
public double denominator = 0; //This will hold the sum of the bigrams of the 2 words
public double res;
public double results;
public Scanner a;
public PrintWriter pw1;
public Sim(){
intialize();
// bigramize();
results = max(res);
System.out.println("\n\nThe Bigram Similarity value between " + words[0] + " and " + words[1] + " is " + res + ".");
pw1.close();
}
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
Sim si=new Sim();
// TODO code application logic here
}
public void intialize() {
int j[]=new int[35];
try {
File file1=new File("input.txt");
File file2=new File("out.txt");
Scanner a = new Scanner(file1);
PrintWriter pw1= new PrintWriter(file2);
int i=0,count = 0;
while (a.hasNext()) {
java.lang.String gram = a.next();
if(gram.startsWith("question")|| gram.endsWith("?"))
{
count=0;
count-=1;
}
if(gram.startsWith("[")||gram.startsWith("answer")||gram.endsWith(" ") )
{
//pw1.println(count);
j[i++]=count;
count=0;
//pw1.println(gram);
//System.out.println(count);
}
else
{
// System.out.println(count);
count+=1;
//System.out.println(count + " " + gram);
}
int line=gram.length();
int sa_length;
//int[] j = null;
int refans_length=j[1];
//System.out.println(refans_length);
for(int k=2;k<=35;k++)
// System.out.println(j[k]);
//System.out.println(refans_length);
for(int m=2;m<=33;m++)
{
sa_length=j[2];
//System.out.println(sa_length);
for(int s=0;s<=refans_length;s++)
{
for(int l=0;l<=sa_length;l++)
{
for (int x = 0; x <= line - 2; x++) {
int tracker = 0;
bigramizedWords[tracker][x] = gram.substring(x, x + 2);
System.out.println(gram.substring(x, x + 2) + "");
//bigramize();
}
// bigramize();
}
}
}
bigramize();
words[tracker] = gram;
tracker++;
}
//pw1.close();
}
catch (FileNotFoundException ex) {
Logger.getLogger(Sim.class.getName()).log(Level.SEVERE, null, ex);
}
}
public void bigramize() {
//for(int p=0;p<=sa_length;p++)
denominator = (words[0].length() - 1) + (words[1].length() - 1);
for (int k = 0; k < bigramizedWords[0].length; k++) {
if (bigramizedWords[0][k] != null) {
for (int i = 0; i < bigramizedWords[1].length; i++) {
if (bigramizedWords[1][i] != null) {
if (bigramizedWords[0][k].equals(bigramizedWords[1][i])) {
matches++;
}
}
}
}
}
matches *= 2;
res = matches / denominator;
}
}
I have tried the above code for bigramizing the words in the file "input.txt" i have got the result of bigram but i didnt get the similarity value.
for e.g:
input file contains as
answer:
high
risk
simulate
behaviour
solution
set
rules
[2]
rules
outline
high
source
knowledge
[1]
set
rules
simulate
behaviour
in the above example I have to compare the words under answer with every word under [2] as {high,rules} {high,outline} {high,high} {high,source} {high,knowledge} and I have to store the maximum value of the above comparison and again the second word from answer is taken and then similar process is taken. At last, mean of maximum value of each iteration is taken.

Method Not Displaying Properly

The method "aboveAverage" in the following code is not displaying correctly and I've tried everything I can. Could someone please explain what's going wrong?
My code:
import java.util.*;
public class DailyCatch
{
private int fishermanID, fisherID;
private String dateOfSample, date;
private double[] fishCaught = new double[10];
private int currWeight = 0;
private String summary;
private double average;
private int aboveAvg;
public DailyCatch() { }
public DailyCatch (int fishermanID, String dateOfSample)
{
fisherID = fishermanID;
date = dateOfSample;
}
public DailyCatch (int fishermanID, String dateOfSample, String weight)
{
this(fishermanID, dateOfSample);
readWeights(weight);
}
public void addFish(double weight)
{
if (currWeight > 10)
{
// array full
}
else
{
fishCaught[currWeight] = weight;
currWeight += 1; // update current index of array
}
}
private void readWeights(String weightsAsString)
{
String[] weightsRead = weightsAsString.split("\\s+");
for (int i = 0; i < weightsRead.length; i++)
{
this.addFish(Double.parseDouble(weightsRead[i]));
}
}
public String toString()
{
return "Fisherman ID: " + fisherID + "\nDate:" + date + "\nFish Caught with Weights: " + Arrays.toString(fishCaught);
}
public void printWeights()
{
for (int i = 0; i < fishCaught.length; i++)
{
System.out.println(fishCaught[i]);
}
}
public double averageWeight()
{
double sum = 0;
double count = 0;
for (int i = 0; i < fishCaught.length; i++)
{
if (fishCaught[i] != 0)
{
sum += fishCaught[i];
count += 1;
average = sum/count;
}
}
return average;
}
public String getSummary()
{ int storyTellerCount = 0;
int keeperCount = 0;
int throwBackCount = 0;
for (int i = 0; i < fishCaught.length; i++)
{
if (fishCaught[i] > 5)
{
storyTellerCount++;
}
else if (fishCaught[i] >=1 && fishCaught[i] <= 5)
{
keeperCount++;
}
else if (fishCaught[i] < 1 && fishCaught[i] > 0)
{
throwBackCount++;
}
} String summary = ("\nStoryteller - " + storyTellerCount+ "\nKeeper - " + keeperCount + "\nThrowback - " + throwBackCount);
return summary;
}
public int aboveAverage()
{
int greatAvgCount = 0;
for (int i = 0; i < fishCaught.length; i++)
{
if (fishCaught[i] > average)
{
aboveAvg = greatAvgCount++;
}
}
return aboveAvg;
}
}
Test Code:
public class BigBass
{
public static void main (String[]args)
{
//Part 1
DailyCatch monday1 = new DailyCatch(32, "4/1/2013", "4.1 5.5 2.3 0.5 4.8 1.5");
System.out.println(monday1);
//Part 2
DailyCatch monday2 = new DailyCatch(44, "4/1/2013");
System.out.println(monday2);
monday2.addFish(2.1);
monday2.addFish(4.2);
System.out.println(monday2);
//Part 3
System.out.println("\n\nSUMMARY OF FISHERMAN 32");
System.out.println(monday1.getSummary());
//Part 4
double avg = monday1.averageWeight();
System.out.printf("\nThere are %d fish above the average weight of %.1f.", monday1.aboveAverage(), avg);
}
}
I just need to get Part 4 to work here. What it does is return that there have been 2 fish caught that are above average when I know it should be 3. The average is 3.1.

A simple mistake.
public int aboveAverage() {
int greatAvgCount = 0;
for (int i = 0; i < fishCaught.length; i++) {
if (fishCaught[i] > 3.1) {
greatAvgCount++; // no 'return'
}
}
return greatAvgCount;
}

if (fishCaught[i] > 3.1)
{
return greatAvgCount++;
}
First try : 4.1 > 3.1
true
returns 0 ++ which is 0 basically
You can increment the counter inside the loop and keep the return statement for the end only.

try
public int aboveAverage() {
int greatAvgCount = 0;
for (int i = 0; i < fishCaught.length; i++) {
if (fishCaught[i] > 3.1) {
greatAvgCount++;
}
}
return greatAvgCount;
}

This line is your problem,
return greatAvgCount++;
you are incrimenting greatAvgCount then returning its initial value, there should be no "return" on this line
The aboveAverage method should be
public int aboveAverage()
{
int greatAvgCount = 0;
for (int i = 0; i < fishCaught.length; i++)
{
if (fishCaught[i] > 3.1)
{
greatAvgCount++;
}
}
return greatAvgCount;
}
Also, you may just be doing it for debug, in which case fair enough, but hardcoding the "average" as 3.1 is generally considered bad practice. If you want average to be always 3.1 (i.e. its a global average that you've looked up from a book then its more usual to declare a static variable called double AVERAGE=3.1 and then use that where ever average is required, that way if the "book value" changes you only need to change average in one place in your code. If average is calculated from your data obviously you should use the calculated value.
Also not directly related to your problem but why are you using an array for your caught fish with a predefined maximum of 10. If you used an ArrayList you could add to it as you saw fit and it would auto expand to accommodate
private double[] fishCaught = new double[10];
becomes
private ArrayList<Double> fishCaught = new ArrayList<Double>();