Thread: Constructor and declaration issues

So I am working on an assignment for my Data Structures class and am getting all confused by how to correctly use an object I created. This object listObj of the SortedListArray class is basically just an integer array that would implement some methods I wrote out (Sort, process, and toString). I just can't seem to pass the array as an argument whenever I call a method.

Errors given whenever I pass intArray as an argument when calling methods:
intArray cannot be resolved to a variable
cannot make a static reference to a non-static method

In the constructor for the object I've just created an int[] with an int argument for the number of indices. Whenever I want to call a method of that object that needs a reference to that array shouldn't I just reference the int array that I created within the constructor?

 
import java.io.*;
import java.util.Scanner;
 
public class SortedListArray implements SortedListInterface
{
	public static void main(String[] args)
	{
		int i=0;
		int noOfInputs = 0;
		int submission = 0;
		int n = 1;
		int num = 0;
 
		Scanner kybd = new Scanner(System.in);
 
		System.out.println("Please enter the number of integers you will put into the array: ");
		noOfInputs = kybd.nextInt();  //holds the user-defined no. of integers to be held within the array
 
		SortedListArray listObj= new SortedListArray(noOfInputs);
 
		for(i = 0; i < noOfInputs; i++)
		{
			kybd.nextLine();
			System.out.println("Please enter integer" + n);
			submission = kybd.nextInt();
			listObj.process(intArray, submission, n);
 
			n++;
		}
 
		System.out.println(listObj.toString(intArray, noOfInputs));
 
		listObj.sort(intArray, noOfInputs);
 
		System.out.println ("Here are the newly sorted entries:\n");
 
		System.out.println(listObj.toString(intArray, noOfInputs));
 
	}
 
	public SortedListArray(int amount)
	{
		int[] intArray = new int[amount];
	}
 
	public void sort(int[] intArray, int inputs) 
	{// pre-conditions: passed arguments must be a valid integer array and integer value
	//  compares an index value at the beginning of the array to the next index value and switches their order
	// from smallest to largest in an ascending manner
	// this is continued for the entire array
		int temp;
		for(int i = 0; i < inputs; i++)
		{
			for(int j = i + 1; j < inputs; j++)
 
			if(intArray[i] > intArray[j])
			{
				temp = intArray[i];
				intArray[i] = intArray[j];
				intArray[j] = temp;	
			}
		}
	}
 
	public String toString(int[] intArray, int inputs)
	{
	//preconditions: Must pass a valid integer array and integer value
	//returns a nicely formatted String value of all of the indices and the values contained within
		String stringFormat = null;
 
		System.out.println ("Current contents of the array are: \n\n");
 
		for (int i = 0; i < inputs; i++)
		{
			stringFormat =(stringFormat + "Index " + i + ": " + intArray[i] + "/n");
		}
		return stringFormat;
	}
 
	public void process(int[] intArray, int inputs, int num)
	{
	//pre conditions: Passed argument must be a valid int array
	//processes the user input and moves them into the array indices
 
		intArray[num] = inputs;
		num++;
	}
 
}

and the interface that it is implementing...

 
 
public interface SortedListInterface {
 
	public void sort(int[] intArray, int inputs);
	// Pre condition: Passed argument is an integer array
	// method reorganizes the contents of the array from smallest to largest
 
	public String toString (int[] intArray, int inputs);
	// pre conditions: Passed arguments must be a valid int array and int variable
	// returns a well-formatted print out of the current contents of the array
 
	public void process(int[] intArray, int inputs, int num);
	//pre conditions: Passed arguments must be a valid int array and int variable
	//processes the user input and moves them into the array indices
 
 
}

By the way, this program just reorganizes integers from lowest to highest within an array, but our teacher wants us to use an ADT to complete it.

Your problem is that you have created the int array inside the SortedListArray constructor. This means it is local and cannot be accessed anywhere else in your program. Maybe you should create an int array in the main method and use that instead.

Ok, sounds good. I can still use the methods created at the bottom with the int array I'll create right? I guess I've only ever used methods on objects I've declared within the class, not variables within the main.

int[] array = new int[someValue];
SortedListArray listObj= new SortedListArray(); // no longer need a constructor in the SortedListArray class
listObj.process(array, 5, 1);

Something like that.

Oh man, so clear now. Thank you.