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Is there an easy way to eliminate the final comma in my output? Number Seperator

For another assignment i needed to program a "number seperator", that splits any given int value into all of its digits and returns it to the main class as a String.
I have the program up and running but there's a small problem with my output.
public class NumberSeperator {
static String splitNumber(int zahl) {
String s = Integer.toString(zahl);
return s;
}
public static void main(String args[]) {
System.out.println("Input a Number: ");
int zahl = readInt();
String ziffern = splitNumber(zahl);
for (int i = 0; i < ziffern.length(); i++) {
System.out.print(ziffern.charAt(i) + ",");
}
}
}
The output of 1234 should be: 1,2,3,4
and the actual output is: 1,2,3,4,
At the risk of sounding extremely stupid, is there an easy fix to this?

How about printing first element without comma and rest in form ,nextElement like
one, two, three
^^^---------------- - before loop
^^^^^----------- - loop iteration
^^^^^^^---- - loop iteration
It can be achieved like:
if(ziffern.length()>0){
System.out.print(ziffern.charAt(0));
}
for(int i=1; i<ziffern.length(); i++){
System.out.print(", "+ziffern.charAt(i));
}
OR you can convert ziffern to String[] array first and use built-in solution which is: String.join(delimiter, data)
System.our.print(String.join(",", ziffern.split("")));

When it's the last iteration, just don't add it.
In the last iteration, it will make the comma empty so that you won't see it after the last value.
String comma=",";
for (int i = 0; i < ziffern.length(); i++) {
if (i == ziffern.length()-1) {
comma="";
}
System.out.print(ziffern.charAt(i) + comma);
}

with Java 8 and streams you can do it in a single command:
String join = Arrays.asList(ziffern.split(""))
.stream()
.collect(Collectors.joining(","));
System.out.println(join);
or with just plain java 8:
String join = String.join(",", ziffern.split(""));
System.out.println(join);

A simple one liner will do your job:
static String splitNumber(int zahl) {
return String.join(",", String.valueOf(zahl).split(""));
}

Quite often this occurs when you know you have at least two items to print. So here is how you could do it then.
String ziffern = splitNumber(zahl);
String output = ziffern[0];
for (int i = 1; i < ziffern.length(); i++) {
output = "," + ziffern[i];
}
System.out.println(output);

You can just output the string without the last character.
Your modified code should be:
public class NumberSeperator {
static String splitNumber(int zahl) {
String s = Integer.toString(zahl);
return s;
}
public static void main(String args[]) {
int zahl = 1234;
String s="";
String ziffern = splitNumber(zahl);
for (int i = 0; i < ziffern.length(); i++) {
s+=ziffern.charAt(i) + ",";
}
System.out.println(s.substring(0,s.length()-1));
}

toString Not Following Correct Format

I am having trouble when I call my toString method and my code isn't following the correct format like it should, this is how I've been trying to call it.
public static void loadQueue(Queue<String> queue, String str) {
String elementArray[] = str.split(",");
for(int i = 0; i < elementArray.length; i++){
queue.push(elementArray[i]);
queue.toString();
}
}
Here is the toString that I want to format it to:
#Override
public String toString() {
String str = "[ ";
if ( !isEmpty() ) {
for (int i = 0; i < queue.length - 1; i++){
str += queue[i] + ", ";
}
str += queue[queue.length - 1] + " ";
}
str += "]";
return str;
Is there a better way to be calling this so that it prints out the correct out put?
Correct format should be [ a, b, c, d ] but all I'm getting is [ abcd ].
Edit, added toString method

If you're trying to use the values between commas in the str as the values to push onto the queue then you don't need to call toString().
Does this work for you?
public static void loadQueue(Queue<String> queue, String str) {
if (null == queue) throw new IllegalArgumentException("Expected non-null queue");
if (null == str) throw new IllegalArgumentException("Expected non-null str");
String elementArray[] = str.split(",");
for(int i = 0; i < elementArray.length; i++){
queue.push(elementArray[i]);
}
}

I can't tell which class your toString override is on, but it wouldn't be on string or queue.
Queue.toString will probably not be what you want. Is there some reason you want to override toString rather than just have a method by another name?
Technique #1
Put all the methods in your existing class
public String queueToString(Queue<String> queue) {
String str = "[ ";
if ( !isEmpty() ) {
for (int i = 0; i < queue.length - 1; i++){
str += queue[i] + ", ";
}
str += queue[queue.length - 1] + " ";
}
str += "]";
return str;
}
...
public static void loadQueue(Queue<String> queue, String str) {
String elementArray[] = str.split(",");
for(int i = 0; i < elementArray.length; i++){
queue.push(elementArray[i]);
}
System.out.println( queueToString(queue) );
}
Technique #2
Create a custom class for your queue and modify the behavior.
public class MyStringQueue extends Queue<String>
{
#Override
/* override the toString method here */
}
...
/* in your class, create an use a MyStringQueue instead of Queue<String> */
public static void loadQueue(MyStringQueue queue, String str) {
String elementArray[] = str.split(",");
for(int i = 0; i < elementArray.length; i++){
queue.push(elementArray[i]);
}
System.out.println( queue.toString() );
}

Constructor Parameter Value Not Implemented

I'm creating a very simple encoder that will shuffle the characters in a string. I've written it to split this string in half, forming two new variables. The user chooses the number of shuffles they want and that is passed as a parameter in the new class constructor -- which should then use that shuffle value throughout the class. Mine is not. The shuffleEncryption method is using the class variable, 0, instead. I know this must be something very obvious, but I am not catching it. :/
//From Main Class
System.out.println("Enter message to encrypt: ");
String message = input.next();
System.out.print("Number of shuffles: " );
int numShuffles = input.nextInt();
ShuffleCipher shuffle = new ShuffleCipher(numShuffles);
System.out.println(shuffle.encode(message));
//The shuffle class
public class ShuffleCipher implements MessageEncoder {
int shuffle;
public ShuffleCipher(int shuffle) {
shuffle = this.shuffle;
}
private String shuffleEncryption(String str) {
int middle = str.length()/2;
int loop = 1;
System.out.println("shift" + shuffle);
StringBuilder sb = new StringBuilder();
do {
String firstHalf = str.substring(0, middle);
System.out.println("first:" + firstHalf);
String secondHalf = str.substring(middle);
System.out.println("second:" + secondHalf);
for(int i = 0, j = 0; i < firstHalf.length(); i++, j++) {
sb = sb.append(secondHalf.charAt(i));
if(j < secondHalf.length()) {
sb = sb.append(firstHalf.charAt(i));
}
str = sb.toString();
}
loop++;
} while (loop <= shuffle);
return str;
}
#Override
public String encode(String plainText) {
String shuffled;
shuffled = shuffleEncryption(plainText);
return shuffled;
}
}

You are not setting the shuffle member variable in the constructor.
Change this:-
public ShuffleCipher(int shuffle) {
shuffle = this.shuffle;
}
to this:-
public ShuffleCipher(int shuffle) {
this.shuffle = shuffle;
}

How do I print a 2d array?

My array is:
String[][] name = new String[15][2];
int rowNumber = 0;
My add button is:
name[rowNumber][0] = firstName.getText();
name[rowNumber][1] = lastName.getText();
I do not know what to put in my list button (lists the first name and last name) into my TextArea called outPut.
The Whole Code:
`
public class StudentGradesView extends FrameView {
String[][] name = new String[15][2];
double[][] testMark = new double[15][4];
int rowNumber = 0;
private void btnAddMouseClicked(java.awt.event.MouseEvent evt) {
name[rowNumber][0] = firstName.getText();
name[rowNumber][1] = lastName.getText();
rowNumber ++;
}
private void btnListMouseClicked(java.awt.event.MouseEvent evt) {
String outputStr = "";
for(int i=0; i < rowNumber; i++) {
outputStr += name[rowNumber][0] + " " + name[rowNumber][1] + "\n";
}outPut.setText(outputStr);
}
}`

Okay, I think I get what you want now.
First we take the inputs...
name[numberOfInputs][0] = firstName.getText();
name[numberOfInputs][1] = lastName.getText();
numberOfInputs += 1;
Now you want to output this to a textarea...
String outputStr = "";
for(int i=0; i < numberOfInputs; i++) {
outputStr += name[i][0] + " " + name[i][1] + "\n";
}
Then set your output textarea
outPut.setText(outputStr);
You are getting nulls because you are specifying a static array size but you (probably) are not filling up the array with test cases up to that amount. So you are printing elements of the array that are simply not populated.
Edit: for comments.

String st = "";
for (int i = 0; i < 15; i++)
st += name[i][0] + " " + name[i][1] + "\n";
outPut.setText(value);
This loops over the array and creates a string containing all the full names, separated by a line break.
This then sets the text using outPut.setText(value);

for(String[] s1d : s2d)
for(String s : s1d)
System.out.println(s);
A simple way using for() construct

The easiest way to print any array to any depth is to use Arrays.deepToString():
System.out.println(Arrays.deepToString(array));

try this:
import java.util.Arrays;
.
.
.
String[][] a = { { "john" },
{ "jones" }
};
System.out.println(Arrays.deepToString(a)); //whole string array
System.out.println(Arrays.deepToString(a[0])); //john
System.out.println(Arrays.deepToString(a[1])); //jones

Java: Printing / returning array from a class

I created a class for a bingo game. I get an error saying "'class' expected". How could I return the values in the array to the main starter?
Any other comments would also be helpful.
Thank you.
import java.util.Random;
public class Card
{
Random generator = new Random();
private final int BOARDMAX = 4;
private final int NUMMAX = 59;
int i, j, m, n;
private int [][] ArrayBoard = new int[BOARDMAX][BOARDMAX];
String [][] StrArrayBoard = new String [BOARDMAX][BOARDMAX];
public void RandomNumGenerator()
{
for (i = 0; i<BOARDMAX; i++)
{
for (j = 0; j<BOARDMAX; j++)
{
ArrayBoard[i][j] = generator.nextInt (NUMMAX+1);
}
}
}
public String ShowBoard()
{
for (i = 0; i<BOARDMAX; i++)
{
for (j = 0; j<BOARDMAX; j++)
{
m=i;
n=j;
if (j != BOARDMAX)
StrArrayBoard[m][n] = ArrayBoard[m][n] + " ";
else
StrArrayBoard[m][n] = ArrayBoard[m][n] + " \n";
}
}
return StrArrayBoard[i][j];
}
public void ShowMark()
{
for (i = 0; i<BOARDMAX; i++)
{
for (j = 0; j<BOARDMAX; j++)
{
if (CardCheck [i][j] == 1)
StrArrayBoard[i][j] = ArrayBoard[i][j] + "* ";
else
StrArrayBoard[i][j] = ArrayBoard[i][j] + " ";
if (j == BOARDMAX)
ArrayBoard[i][j] = ArrayBoard[i][j] + "\n";
}
}
}
public String toString()
{
return ArrayBoard[][];
}
}

With toString() you need to return a String object but actually you try to return an int[][]. The same is true for ShowBoard, you try to return an array of Stringarrays which is not a compatible type.
Here's the fix:
public String ShowBoard() {
// your code to populate StrArrayBoard
StringBuilder boardBuilder = new StringBuilder();
for (String[] row:StrArrayBoard)
for (String cell:row)
sb.append(cell);
return boardBuilder.toString();
}
public String toString() {
return ShowBoard();
}
I suggest to refactor the code and rename methods and fields:
ShowBoard() --> getBoardAsString()
ArrayBoard --> arrayBoard
StrArrayBoard --> strArrayBoard
And there's no need to declare StrArrayBoard as a field (class member) just because you only need it inside the ShowBoard method. Declare it there as a local variable.

Adding to the bugs others have pointed:
You have if (CardCheck [i][j] == 1), but the array CardCheck is not declared anywhere.
You have ArrayBoard[i][j] = ArrayBoard[i][j] + "\n"; but ArrayBoard is an int array, you cannot add a string "\n" to it's member.

The compiler will complain because of the error on your code:
public String toString()
{
return ArrayBoard[][];
}
It can't convert int[][] (which is your ArrayBoard) to String. My suggestion is that you populate all values stored in StrArrayBoard in a StringBuffer and return the StringBuffer.toString() in the toString() method.
The toString() method requires a String.
Hope this helps.

public String toString()
{
return ArrayBoard[][];
}
This method expects to return a String but you are returning a 2D Integer array, what you need is a String. the toString() method returns a string representation of the object, so in this case, what you can do is to use a StringBuilder to build the string representation of the array and then, use the .toString() of the StringBuilder to return the string representing the 2D Array.
Also, as noted by Alois Cochard, you variable naming does not follow convention. Variable names in Java use a camel case notation.

I for one don't really understand your question but I've got a couple of comments.
The class variables i and j should be local variables in each method.
Your naming convention is nonstandard, seems like a more C# convention. Start variable and method names with a lower case.
CardCheck isn't defined anywhere. I presume it is meant to indicate if a number on a square has been checked, in which case it should be a boolean and not an int.
toString doesnt return a string. You can use Arrays.toString to help you.
Similarily, ShowBoard just returns one element of an array, you probably wanted to show the entire board there.
For your toString and ShowBoard methods you probably want to use a StringBuilder to build up the string representation.
StringBuilder builder = new StringBuilder();
for (int i=0; i<BOARDMAX; i++) {
for (int j=0; j<BOARDMAX; j++) {
builder.append(StrArrayBoard[i][j]);
}
builder.append('\n');
}
return builder.toString();

Here's a version of your class that compiles (and I changed some field names and modifiers to adhere to standard conventions). Try this:
public class Card{
private final Random generator = new Random();
private static final int BOARDMAX = 4;
private static final int NUMMAX = 59;
int i, j, m, n;
private final int[][] arrayBoard = new int[BOARDMAX][BOARDMAX];
private final String[][] strArrayBoard = new String[BOARDMAX][BOARDMAX];
// do something here please
private int[][] CardCheck;
public void RandomNumGenerator(){
for(i = 0; i < BOARDMAX; i++){
for(j = 0; j < BOARDMAX; j++){
arrayBoard[i][j] = generator.nextInt(NUMMAX + 1);
}
}
}
public String ShowBoard(){
for(i = 0; i < BOARDMAX; i++){
for(j = 0; j < BOARDMAX; j++){
m = i;
n = j;
if(j != BOARDMAX){
strArrayBoard[m][n] = arrayBoard[m][n] + " ";
} else{
strArrayBoard[m][n] = arrayBoard[m][n] + " \n";
}
}
}
return strArrayBoard[i][j];
}
public void ShowMark(){
for(i = 0; i < BOARDMAX; i++){
for(j = 0; j < BOARDMAX; j++){
if(CardCheck[i][j] == 1){
strArrayBoard[i][j] = arrayBoard[i][j] + "* ";
} else{
strArrayBoard[i][j] = arrayBoard[i][j] + " ";
}
if(j == BOARDMAX){
// this is probably what you mean:
strArrayBoard[i][j] = arrayBoard[i][j] + "\n";
}
}
}
}
#Override
public String toString(){
// this is probably what you mean:
return Arrays.deepToString(strArrayBoard);
}
}