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How to I call a method to create arrays from another class?

So I have this code in the main class
public class OneDArrays
{
public static int[] create (int size)
{
int[] a1 = new int[size];
for (int i = 0; i < size; i++)
{
a1[i] = i*2+1;
}
return a1;
}
public int sumSome (int[] b1, int howmany)
{
int sum = 0;
if (howmany <= b1.length)
{
for (int i = 0; i < howmany; i++)
{
sum = sum + b1[i];
}
}
else
{
sum = -1;
}
return sum;
}
public int[] grow (int[] c1, int extra)
{
int[] newArray = new int[c1.length+extra];
for (int i = 0; i < newArray.length; i++)
{
while (i <= c1.length)
{
newArray[i] = c1[i];
i++;
}
newArray[i] = 0;
}
return newArray;
}
public void print (int[] d1)
{
for (int i = 0; i < d1.length; i++)
{
System.out.println (d1[i] + ", ");
}
}
}
And then I have my tester class,
public class OneDArraysTester
{
public static void main (String[] args)
{
int[] test1;
test1.create (5);
}
}
How do retrieve the method from the first class? I get the error that "create" is an undeclared method. If the "create" method were a constructer, I know I could just type create test1 = new create (5) but I don't see a way to turn it in to a constructer, so what's the way of doing that but for a method?

You invoke a static method with the classname. Literally className.methodName. Like,
int[] test1 = OneDArrays.create(5);

You have made a class named OneDArrays so you can call it's methods by creating an instance or object of that class.
like this :
OneDArrays ObjectOfClass = new OneDArrays();
int test1[] = ObjectOfClass.create(5);
similarly you can also call other methods of that class by accessing methods of this newly created object ObjectOfClass.
like :
sumOfArray = ObjectOfClass.sumSome(test1,3);
int biggerTest1[] = ObjectOfClass.grow(test1,10);
If you want to make create method works as a constructor than you can but you cannot return value from a constructor so you cannot return your array from that constructor.

Since you have declared the create method as static, #ElliotFrisch is the best way. But, it is not always a good idea to make methods static. So another way to achieve what you want would be to make the create method non-static.
public int[] create (int size){/*Method Body*/};
And then create an object of the OneDArray class to access the method.
OneDArrays oneDArrays = new OneDArrays();
int[] test1 = oneDArrays.create(5);
or,
int[] test1 = new OneDArrays().create(5);

Calling a variable into another method in java

Does anyone know how to call a variable into another method? Doing an assignment for school and really struggling. (Variable that I want to call is arrayOfEarth by the way.)
public static void readDataArray(String filename) throws FileNotFoundException {
Scanner input = new Scanner(new BufferedReader(new FileReader("sample.xyz")));
int rows = 2500000;
int columns = 3;
double[][] arrayOfEarth = new double[rows][columns];
while (input.hasNextLine()) {
for (int a = 0; a < arrayOfEarth.length; a++) {
String[] line = input.nextLine().trim().split("/t ");
for (int b = 0; b < line.length; b++) {
arrayOfEarth[a][b] = Double.parseDouble(line[b]);
}
}
}
System.out.println(Arrays.deepToString(arrayOfEarth));
}
public static List<Double> CoordinatesAbove(double altitude) {
List<Double> CoordinatesAbove = new ArrayList<>();
for (int c = 0; c < arrayOfEarth.length; c++) {
CoordinatesAbove.add(arrayOfEarth[c][2]);
}
CoordinatesAbove.removeIf(d -> d < altitude);
return CoordinatesAbove;
}

Just move it to the class level and make it static (otherwise the static method can't use it)
private static double[][] arrayOfEarth;
public static void readDataArray(String filename) throws FileNotFoundException {
Scanner input = new Scanner(new BufferedReader(new FileReader("sample.xyz")));
int rows = 2500000;
int columns = 3;
arrayOfEarth = new double[rows][columns];
while (input.hasNextLine()) {
for (int a = 0; a < arrayOfEarth.length; a++) {
String[] line = input.nextLine().trim().split("/t ");
for (int b = 0; b < line.length; b++) {
arrayOfEarth[a][b] = Double.parseDouble(line[b]);
}
}
}
System.out.println(Arrays.deepToString(arrayOfEarth));
}
public static List<Double> CoordinatesAbove(double altitude) {
List<Double> CoordinatesAbove = new ArrayList<>();
for (int c = 0; c < arrayOfEarth.length; c++) {
CoordinatesAbove.add(arrayOfEarth[c][2]);
}
CoordinatesAbove.removeIf(d -> d < altitude);
return CoordinatesAbove;
}

Make your readDataArray method return the value to the caller, and have whoever is calling the CoordinatesAbove method pass the value to it.
To return the value and to accept it as a parameter:
public static double[][] readDataArray(String filename) throws FileNotFoundException {
...
System.out.println(Arrays.deepToString(arrayOfEarth));
return arrayOfEarth;
}
public static List<Double> CoordinatesAbove(double altitude, double[][] arrayOfEarth) {
...
}
To capture the return value of readDataArray and to pass it to CoordinatesAbove:
double[][] arrayOfEarth = readDataArray(...)
List<Double> list = CoordinatesAbove(altitude, arrayOfEarth);
It is arguably better to make the flow of information explicit like this, than hiding the flow by writing the results to a common global variable in one method and reading the variable in the other.

Array Method issue

having a problem with my java program. I am a newbie to Java and just can't figure out what is exactly the issue with it. In short I've declared an array and a variable in main, I've created my method call and would like my array be passed into my method with the variable. I would then like the method to take my array and count the number of times my variable "8" occurs, get rid of the 8 out of the array and return a new smaller array back to main. Here is my code below. I feel as if I am just missing one block code any suggestions?
public class Harrison7b
{
public static void main(String [] args)
{
int[] arrayA = {2,4,8,19,32,17,17,18,25,17,8,3,4,8};
int varB = 8;
// Call with the array and variable you need to find.
int[] result = newSmallerArray(arrayA, varB);
for(int x = 0; x < arrayA.length; x++)
{
System.out.print(arrayA[x] + " ");
}
}
public static int[] newSmallerArray( int[] arrayA, int varB)
{
int count = 0;
for(int x = 0; x < arrayA.length; x++)
{
if(arrayA[x] == varB)
{
count++;
}
}
int [] arrayX = new int[arrayA.length - count];
for(int B = 0; B < arrayA.length; B++)
{
if(arrayA[B] != varB)
{
}
}
return arrayX;
}
}

you do not actually need to return the array because when you pass an array to a method you also pass its memory address meaning its the same address that you change so, it will also change the arraysA of main method because you are just changing the values of the same memory adress
import java.util.*;
public class Help
{
public static void main(String[] args)
{
ArrayList<Integer> arraysA = new ArrayList<Integer>();
arraysA.add(Integer.valueOf(2));
arraysA.add(Integer.valueOf(4));
arraysA.add(Integer.valueOf(8));
arraysA.add(Integer.valueOf(19));
arraysA.add(Integer.valueOf(32));
arraysA.add(Integer.valueOf(17));
arraysA.add(Integer.valueOf(17));
arraysA.add(Integer.valueOf(18));
arraysA.add(Integer.valueOf(25));
arraysA.add(Integer.valueOf(17));
arraysA.add(Integer.valueOf(8));
arraysA.add(Integer.valueOf(3));
arraysA.add(Integer.valueOf(4));
arraysA.add(Integer.valueOf(8));
int varB=8;
newSmallerArray(arraysA,varB);
for(Integer i:arraysA)
{
System.out.println(i);
}
}
public static void newSmallerArray(ArrayList<Integer> arraysA,int varB)
{
for(int i=0;i<arraysA.size();++i)
{
if(Integer.valueOf(arraysA.get(i))==varB)
{
arraysA.remove(i);
}
}
}
}

Try this code it will not require for loop:
List<Integer> list = new ArrayList<Integer>(Arrays.asList(arrayA));
list.removeAll(Arrays.asList(8));
arrayA = list.toArray(array);

What am I doing wrong with using arrays?

I'm trying to fill an array using a method and later print that array out.
However when I try to do so all it gives me are zeroes. I think my fill method is not working properly but I'm not sure why. I'm trying to understand arrays but so far no good. I would prefer an explanation rather than an answer. If I can get this myself it would be best.
import java.util.Scanner;
public class diverScore {
static double score = 0;
static double validDegreeOfDiff = 0;
public static void main(String[] args) {
double[] score = new double[6];
inputAllScores(score);
printArray(score);
}
public static double[] inputAllScores(double[] x) {
Scanner s = new Scanner(System.in);
double[] array_score = new double[6];
for (int i = 0; i < 6; i++) {
System.out.println("What is the score given by the judge?");
array_score[i] = s.nextDouble();
}
return array_score;
}
public static void printArray(double[] j) {
for (int i = 0; i < 6; i++) {
System.out.println("The array is:" + j[i]);
}
}
}

In your inputAllScores, you're writing to a new local array, and returning it, but you're not using the returned array. It would be better if you wrote to the array that you passed into that method (which inside the method is called x).

try
import java.util.Scanner;
public class DiverScore {
static double score = 0;
static double validDegreeOfDiff = 0;
public static void main(String[] args) {
// double[] score = new double[6];
double[] score = inputAllScores(/*score*/);
printArray(score);
}
public static double[] inputAllScores(/*double[] x*/) {
Scanner s = new Scanner(System.in);
double[] array_score = new double[6];
for (int i = 0; i < 6; i++) {
System.out.println("What is the score given by the judge?");
array_score[i] = s.nextDouble();
}
return array_score;
}
public static void printArray(double[] j) {
for (int i = 0; i < 6; i++) {
System.out.println("The array is:" + j[i]);
}
}
}

double[] score = new double[6];
This line simply initializes an array of type double with 6 indexes allocated for it, with each resulting in 0 when printed out.
You could simply change the code in main to this, thus actually using the return value of the inputAllScores function.
public static void main(String[] args) {
double[] score = new double[6];
printArray(inputAllScores(score));
}
HTH

How to fill my array from another class?(Java)

This is my program that makes some calculations to a numbers into the array named "initialMarks". However I would like to fill the initialMarks array from another class using scanner.Could you help me to figure it out how to do that? Is it possible to outprint the result array "result" in a third class?
public class testingN
{
public static void main(String[] args)
{
int [] initialMarks = new int [4];
int [] result = new int [6];
result[0] = computedMarks(initialMarks[0], initialMarks[1])[0];
result[1] = computedMarks(initialMarks[2], initialMarks[3])[1];
for(int i=0; i< result.length; i++)
System.out.println(result[i]);
}
public static int [] computedMarks(int mark1, int mark2)
{
int [] i= new int [6];
for (int j = 0; j < i.length; j++)
{
if ((mark1 < 35 && mark2 > 35) || (mark1 > 35 && mark2 < 35))
{
i[j] = 35;
}
else
{
i[j] = (mark1 * mark2);
}
}
return i;
}
}

Your other class can have a method that returns a stream, and you can feed that into your Scanner's constructor.
In your other class's String getInitialMarks() method:
// Generate a string with all the "marks" as "stringWithMarks", separated by "\n" characters
InputStream is = new ByteArrayInputStream( stringWithMarks.getBytes( "UTF-8" ) );
return is;
Then in your first class, otherClass:
Scanner scanner = new Scanner(otherClass.getInitialMarks());
And proceed to read in the marks as if it were user input.

public class testingN
{
static int [] result = new int [6];
static int [] initialMarks = new int [4];
public static void main(String[] args)
{
Declaring result as class member (global variable) and being static should help your cause
Example: using from another class
public class AnotherClass {
public static void main(String[] args) {
// example
testingN.result[0] = 4;
System.out.println(testingN.result[0]);
}
}
Edit: Run the code below Here. You'll see it works just fine.
class testingN
{
static int [] result = new int [6];
static int [] initialMarks = new int [4];
}
public class AnotherClass {
public static void main(String[] args) {
// example
testingN.result[0] = 4;
System.out.println(testingN.result[0]);
}
}