Thread: need help

my teacher posted this exercise and i still dont understand how to do it. i fixed some of the little things that i knew how to fix but the rest of it im not sure of. can anyone help?

It's better if you post all of your code, see how to in my signature.

also, it's kinda hard to help when we don't know what's going wrong.

What are you trying to do?

Wow, your user name pretty much sums it up. Read this before posting another question: How To Ask Questions The Smart Way

This wouldn't hurt either: SSCCE

sorry its my first post thats why all the code wasnt shown. and if the errors and output isnt what you meant sorry

import java.util.Scanner;
 
public class Test3Program
{
   public static void main(String[] args)
	{
 
 
		// Replace the ??? with the appropriate constructor.  
	[exception] Scanner myIn = new ???; [/exception]
 
		String itemDescription;  // Temporary variable to hold each description entered
 
		String scanResult;  // Temporary String variable to hold each value entered
 
		double itemValue;  // Temporary double variable to hold each value converted from scanResult 
 
		int numOfDataItems,  // Number of data items to enter/entered
		    minLoc,          // Location of the minimum element.
			 maxLoc;          // Location of the maximum element.
 
		do
		{
		   System.out.print("Please enter the number of data items (minimum of 10 items): ");
 
		   // Replace the ??? with the appropriate method to parse the String read into an integer.
		   numOfDataItems = Integer.parseInteger(myIn.nextLine());
		}
		while  (numOfDataItems < 10); // Enter at least 10 data points
 
		Item[] dataItems = new Item[numOfDataItems];  // Create an array of Items
 
		// Replace the ??? with the appropriate item to control the loop to enter all of the data points.
	[exception]	for (int count=0; count<dataItems.???; count++) [/exception]
		{
		   System.out.print("Please enter a description of data item #"+(count+1)+": ");
 
			itemDescription = myIn.nextLine();
 
		   System.out.print("Please enter the value of data item #"+(count+1)+": ");
 
			scanResult = myIn.nextLine();
 
			itemValue = Double.parseDouble(scanResult);
 
			// Replace the ??? with the appropriate identifier for the array index
	[exception]	dataItems[???] = new Item(itemDescription, itemValue); [/exception]
		}
 
		double min = dataItems[0].getValue(), 
		       max = dataItems[0].getValue(),
				 sum = dataItems[0].getValue();
 
		minLoc = 0;
		maxLoc = 0;
 
		for (int count = 1; count<dataItems.length; count++)
		{
		   // Replace the ??? with the appropriate identifier for the array index to accumulate the values in the sum.
		[exception]   sum = sum + dataItems[???].getValue(); [/exception]
 
		   if (dataItems[count].getValue() < min)
			{
			   min = dataItems[count].getValue();
				minLoc = count;
			}
			else if (dataItems[count].getValue() > max)
			     {
			        // Replace the ??? with the appropriate array element
			   [exception]     max = dataItems[???].getValue(); [/exception]
					  maxLoc = count;
				  }
		}
[console]		
		double average = sum / numOfDataItems;
 
		System.out.println("The highest value of the data values was "+max+".");
		System.out.println("The highest value item is described as a(n):" + dataItems[maxLoc].getDescription()+".");
 
		// Replace the ??? with the appropriate identifier
		System.out.println("The lowest value of the data values was "+min+".");
		System.out.println("The lowest value item is described as a(n):" + dataItems[minLoc].getDescription()+".");
 
		System.out.println("The average of the item's data values was "+average+".");
 
		// Replace the ??? with the data item at the position equal to the last digit of your student ID number.
		System.out.println(???);  // Include the description and value of data item.
	[/console]	
	}
}

im not sure if u needed to see this one too but it cant hurt

// Class - Item (used to contain a value and description of the value).
public class Item
{
   private String description;
	private double value;
 
	public Item()  // Default constructor.
	{
	   this("", 0.0);
	}
 
	public Item(String description, double value)  // Detailed constructor.
	{
	   setDescription(description);
		setValue(value);
	}
 
	public void setDescription(String description)   // Set the object's description attribute.
	{
	   this.description = description;
	}
 
	public void setValue(double value)  // Set the object's value attribute.
	{
	   this.value = value;
	}
 
	public String getDescription()  // Return a String containing the object's description attributes.
	{
	   return this.description;
	}
 
	public double getValue()  // Return a double containing the object's value attributes.
	{
	   return this.value;
	}
 
	public String toString()  // Return a String containing all of the object's attributes.
	{
	   return "Description: "+getDescription()+"\n"+
		       "Value: "+getValue()+"\n";
	}
 
}

@kevinworkman
its my first post and ive only been using java for about a month and a half, granted that might be enough time to figure this out but my teacher isnt the best, so i have to go off of guessing alot of the time

Are you scanning from a file or from the console?

If from the console

do something like

Scanner console = new Scanner(System.in);

if from a file

Scanner input = new Scanner("FileName.extension");
and, if from a file, your main method needs to throw a FileNotFoundException

like this

public static void main(String[] args) throws FileNotFoundException

Have an array of Items that are the length of number of items entered by Scanner.

Item[] items = new Item[numOfDataItems];

Have a for loop for each item

for (int i =0; i < items.length; i++)
{
System.out.println("Enter Description for item " + (i+1) + ".");
itemDescription = myIn.nextLine();
System.out.print("Please enter the value of data item #"+(count+1)+": ");

scanResult = myIn.nextLine();

itemValue = Double.parseDouble(scanResult);

items[i] = new Item(itemDescription, itemValue);
}

double min = dataItems[0].getValue(),
double max = dataItems[0].getValue(),
double sum = dataItems[0].getValue();

max = dataItems[???].getValue();
replace ??? with
count
That's your variable in the for loop.

Originally Posted by Lazy

@kevinworkman
its my first post and ive only been using java for about a month and a half, granted that might be enough time to figure this out but my teacher isnt the best, so i have to go off of guessing alot of the time

That's why I posted the two links. Did you read them? Where's your SSCCE? What errors are you seeing? Are they Exceptions? Is the program acting differently from what you're expecting? What are you expecting? What happens instead? Point out any line numbers from the Exceptions' stack trace in the SSCCE that you post so that we don't have to count.

Originally Posted by KevinWorkman

That's why I posted the two links. Did you read them? Where's your SSCCE? What errors are you seeing? Are they Exceptions? Is the program acting differently from what you're expecting? What are you expecting? What happens instead? Point out any line numbers from the Exceptions' stack trace in the SSCCE that you post so that we don't have to count.

the SSCCE i dont have one. my teacher just said heres an exercise and you have the weekend to fix it. the other stuff i honestly dont know he never provides/provided an answer key for us to look at until we get to class

import java.util.Scanner;
 
public class Test3Program
{
   public static void main(String[] args)
	{
 
 
		// Replace the ??? with the appropriate constructor.  
		Scanner myIn = new Scanner(Item.java);
 
		String itemDescription;  // Temporary variable to hold each description entered
 
		String scanResult;  // Temporary String variable to hold each value entered
 
		double itemValue;  // Temporary double variable to hold each value converted from scanResult 
 
		int numOfDataItems,  // Number of data items to enter/entered
		    minLoc,          // Location of the minimum element.
			 maxLoc;          // Location of the maximum element.
 
		do
		{
		   System.out.print("Please enter the number of data items (minimum of 10 items): ");
 
		   // Replace the ??? with the appropriate method to parse the String read into an integer.
		   numOfDataItems = Integer.parseInteger(myIn.nextLine());
		}
		while  (numOfDataItems < 10); // Enter at least 10 data points
 
		Item[] dataItems = new Item[numOfDataItems];  // Create an array of Items
 
		// Replace the ??? with the appropriate item to control the loop to enter all of the data points.
		for (int count=0; count<dataItems.length; count++)
		{
		   System.out.print("Please enter a description of data item #"+(count+1)+": ");
 
			itemDescription = myIn.nextLine();
 
		   System.out.print("Please enter the value of data item #"+(count+1)+": ");
 
			scanResult = myIn.nextLine();
 
			itemValue = Double.parseDouble(scanResult);
 
			// Replace the ??? with the appropriate identifier for the array index
			dataItems[count+1] = new Item(itemDescription, itemValue);
		}
 
		double min = dataItems[0].getValue(), 
		       max = dataItems[0].getValue(),
				 sum = dataItems[0].getValue();
 
		minLoc = 0;
		maxLoc = 0;
 
		for (int count = 1; count<dataItems.length; count++)
		{
		   // Replace the ??? with the appropriate identifier for the array index to accumulate the values in the sum.
		   sum = sum + dataItems[count].getValue();
 
		   if (dataItems[count].getValue() < min)
			{
			   min = dataItems[count].getValue();
				minLoc = count;
			}
			else if (dataItems[count].getValue() > max)
			     {
			        // Replace the ??? with the appropriate array element
			        max = dataItems[count].getValue();
					  maxLoc = count;
				  }
		}
 
		double average = sum / numOfDataItems;
 
		System.out.println("The highest value of the data values was "+max+".");
		System.out.println("The highest value item is described as a(n):" + dataItems[maxLoc].getDescription()+".");
 
		// Replace the ??? with the appropriate identifier
		System.out.println("The lowest value of the data values was "+min+".");
		System.out.println("The lowest value item is described as a(n):" + dataItems[minLoc].getDescription()+".");
 
		System.out.println("The average of the item's data values was "+average+".");
 
		// Replace the ??? with the data item at the position equal to the last digit of your student ID number.
		System.out.println("???");  // Include the description and value of data item.
 
	}
}

i have 2 exceptions in this after compiling. the "(error)" is where the ^ is supposed to be.

 

Test3Program.java:16: cannot find symbol

symbol  : variable java

location: class Item

		Scanner myIn = new(error) Scanner(Item.java);

		                               ^

Test3Program.java:33: cannot find symbol

symbol  : method parseInteger(java.lang.String)

location: class java.lang.Integer

		   numOfDataItem(error)s = Integer.parseInteger(myIn.nextLine());

		                           ^

2 errors

one other thing im not sure of is if this looks right... line 52/53
// Replace the ??? with the appropriate identifier for the array index
dataItems[count+1] = new Item(itemDescription, itemValue);

What is Item.java? Is it a file? Do you mean "Item.java"? Take a look at the Scanner API to see what kinds of arguments its constructors take.

Similarly, consult the API for Integer. Where do you see a parseInteger method?

Java Platform SE 6

Originally Posted by KevinWorkman

What is Item.java? Is it a file? Do you mean "Item.java"? Take a look at the Scanner API to see what kinds of arguments its constructors take.

Similarly, consult the API for Integer. Where do you see a parseInteger method?

Java Platform SE 6

yes, item.java is a file, if were to put quotes around it then wouldnt that show up as written text? and the parseInteger is the way my teacher puts it in there and it works when he does it so i dont change it

Originally Posted by Lazy

yes, item.java is a file, if were to put quotes around it then wouldnt that show up as written text? and the parseInteger is the way my teacher puts it in there and it works when he does it so i dont change it

Look at the API for Scanner to see how to properly load files.

Scanner (Java Platform SE 6)