Help!!! Storing user input and reuse the entered value in printf() statement

Question

I'm a begginer to programing and I'm working on my first project. I'm trying to user the user input value and reuse that value in a sensence. The requirement is that I need to use System.in to read user input and System.out to print.

Issue: Method jar.getItemName() and jar.getItemNumber() take-in NEW user input everytime I call them as printf() parameters.

Target: I need to STORE the original user input and reuse the stored value in a sentence with printf().

Attempts: 1) Assigned the methods above to a variable. 2) Pass a declared variable into nextInt() and nextLine(). 3) Pass the String itemName and int itemNumber as printf() parameters. All of the above resulted in compile errors.

I'm STOCK please help!!!

I've made a Jar class and game class.

Jar class

import java.util.Scanner;

class Jar { public String itemName; public int itemNumber;

Scanner Name = new Scanner(System.in);
Scanner Number = new Scanner(System.in);

public Jar (String itemName){
    this.itemName = itemName;
}

public Jar (int itemNumber){
    this.itemNumber = itemNumber;
}

public String getItemName() { String itemName = Name.nextLine(); return itemName; }
public int getItemNumber(){ int itemNumber = Number.nextInt(); return itemNumber; } }

Game class

public class Game {

public static void main(String[] args) { // Your amazing code goes here...

    Jar jar = new Jar("");

    System.out.printf("ADMINITRATOR SETUP %n**************************%n");
  System.out.printf("Name of the item in the jar: ");
System.out.printf("The maximum number of %s in the jar: ", jar.getItemName());
    jar.getItemNumber();
    System.out.println("");

    System.out.printf("PLAYER %n**************************%n");

    System.out.printf("The maximum number of %s in the jar is %d. %n", jar.getItemName(),jar.getItemNumber());

    System.out.printf("Guess:    %n");

}

}

Answer 1 · 2017-04-03T17:28:28Z

April 3, 2017 5:28pm

Sure.

First its important to understand access restrictions in Java (I'm not familiar with the curriculum here as I learned it during university). This table from stack overflow is a good summary:

           | Class | Package | Subclass | Subclass | World
            |       |         |(same pkg)|(diff pkg)| 
————————————+———————+—————————+——————————+——————————+————————
public      |   +   |    +    |    +     |     +    |   +     
————————————+———————+—————————+——————————+——————————+————————
protected   |   +   |    +    |    +     |     +    |   o     
————————————+———————+—————————+——————————+——————————+————————
no modifier |   +   |    +    |    +     |     o    |   o
————————————+———————+—————————+——————————+——————————+————————
private     |   +   |    o    |    o     |     o    |   o

+ : accessible
o : not accessible

Right now you are using public/no modifier declarations when you declare variables and methods so their access isn't restricted. Here is an example of public/private use:

public class Foo{
   public int num1 = 1;
   private int num2 = 2;

}

public class Bar{

   Foo foo = new Foo();

   public int num1Test = foo.num1;   //Here we directly access the var in Foo, and its OK
   public int num2Test = foo.num2; //Here we try and access the private var in Foo, and this is NOT ok
}

what <strong>getters</strong> and <strong>setters</strong> allow for us to do is to bypass some of these restrictions as we choose, so we can limit the scope that other pieces of code can access our data. These are simple methods that control the flow and are typically in this form:

  public int getNum2(){
     return num2;
}

public void setNum2(int value){
    num2 = value;
}

if we define those methods in the class Foo above, we can do the following:

public class Foo{
   public int num1 = 1;
   private int num2 = 2;

  public int getNum2(){
       return num2;
  }

  public void setNum2(int value){
      num2 = value;
  }

}

public class Bar{
   public int num1Test = foo.num1;   //Still OK;
   public int num2Test = foo.getNum2(); //Now it works!

  foo.setNum2(17);  //We can also change the variable now using a setter!
}

Basically they are simple methods used for access control. Here's a final example of why that my be important:

  public void setNum2(int value){
      if(value == 42){
         throw new IllegalArgumentException();  //Throw an error if someone tries to set our value to a specific number
      } else{
         num2 = value;
      }
  }

Maybe its not entirely relevant to your problem, but its a nice trick to be aware of.

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Help!!! Storing user input and reuse the entered value in printf() statement

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Ryan Schron

Ryan Schron

Jun Kakeno

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