You've defined the Number class, but have not provided a toString() method. So, when each Number object is printed, the Object.toString() method is used. The Object.toString() prints essentially an object ID. It's the class name an the hashcode.

So, a partial fix to your code is to add a toString() method to the definition of the Number class. For example,

 public String toString() {
   return String.valueOf(int_width);
 }

But, I don't see any place in your code where the value of the Number is being stored. In the toString() method I provided above, I assumed that the int_width field was supposed to contain the value.

Wow, Phil thanks for your time....

I worked through your code and tried to modify it again. I can now enter and sort my integer-values, and I now want them to be displayed as rectangles. So every time you type in a value, a rectangle is drawn on the screen and its width depends on the current value you've just entered.

Problem: I use this for-loop, but it does not work yet, as I have only int-values in my rect function and numbers.get(i) is an object....

Code:

  for (int i = 0; i<numbers.size(); i++) {
    fill (0);
    rect (i*20,10, numbers.get(i) ,5);
  }
 

I wrote this in the draw() function so that it is constantly updated.

So all I need to do is to get numbers.get(i) into an int as well...as this is still an Object I cannot draw my rectangles. Any idea how this might work?

I've googled to find a way to convert it like using "parseInt" but that does not work....

thanks a lot for your time and energy

Ok that's what I was looking for.

I now put it all together like this.

Code:

ArrayList numbers; 
int o1;
void setup() { 
  size (400,400);
  numbers = new ArrayList(); 
  numbers.add(new Number()); 
} 

void draw () { 
 for (int i = 0; i < numbers.size(); i++) { 
    fill(0); 
    Number n = (Number) numbers.get(i); // You have to cast back objects from a Collection 
    rect(i*20, 10, n.getValue(), 5); 
} 
} 

class Number implements Comparable { 
  StringBuilder buffer; 
  Number() { 
    buffer = new StringBuilder(); 
  } 
  void update(char c) { 
    // Might check c before adding it 
    buffer.append(c);     
  } 
  int getValue() { 
  return Integer.valueOf(buffer.toString());
  } 
  String toString() { 
    return buffer.toString(); 
  } 
  public int compareTo(Object o) { 
    Number n = (Number) o; 
    int i1 = getValue(); 
    int i2 = n.getValue(); 
    return i1 == i2 ? 0 : (i1 > i2 ? 1 : -1); 
  } 
} 

void keyReleased() { 
  boolean bDisplay = false; 
  if (keyCode == ENTER) { 

    bDisplay = true; 
    println(""); 
  } 
  else { 
    // Update latest number 
    Number n = (Number) numbers.get(numbers.size() - 1); 
    n.update(key); 
    print(key); 
  } 
  if (bDisplay) { 
    Collections.sort(numbers); 
    println(numbers); 
    numbers.add(new Number()); 
  } 
}
 

It gives me an error when executing the script.
Code:

 int getValue() { 
  return Integer.valueOf(buffer.toString());
  } 
 

The error is named as: NumberFormatException: For input string ""

I think it is because when starting the script there are no values yet to use. So  I tried to make a counter so that the for-loop is only executed when the mouse is released once. That works so far as if I don't get an error right from the beginning. But as soon as I typed in some values and clicked the mouse the same error occurs....

any idea what might be still wrong?

Ok this is my code so far....
When typing in a number you can see the the typed number as the width of the current rect.
Let's say you type in these numbers 10, 20, 30. Then you can see 3 rects right underneath each other. But when you now type in 25 this 4th rect should be 5 pixels smaller than the 3rd rect which is 30 pixels wide. But as soon as you type in a smaller number th rect is automatically as long as the highest number.

I dont get why because before you press Enter the correct size is shown in the window.
Because what I finally want to do is, that you can first of all type in many number and all rects have a different size. And when you Click the mouse the screen is deleted and the rects (and also the numbers) are sorted by size....
I hope you get what I mean.... :/ Can you help me again? I think we're close to solve the whole problem......thanks a lot

I thought that the for-loop inside the draw()-Function only cares for the last typed-in number....

Code:

ArrayList numbers; 
void setup() { 
  size (400,400);
  numbers = new ArrayList(); 
  numbers.add(new Number()); 
} 

void draw () { 
  for (int i = 0; i < numbers.size(); i++) { 
    fill(0); 
    Number n = (Number) numbers.get(i); // You have to cast back objects from a Collection 
    rect(20, i*10, n.getValue(), 5); 
  }
} 

class Number implements Comparable { 
  StringBuilder buffer; 
  Number() { 
    buffer = new StringBuilder(); 
  } 
  void update(char c) { 
    // Might check c before adding it 
    buffer.append(c);     
  } 
  int getValue() {   
    if (buffer.length() == 0) 
	return 0; 
    return Integer.valueOf(buffer.toString()); 
  }
  String toString() { 
    return buffer.toString(); 
  } 
  public int compareTo(Object o) { 
    Number n = (Number) o; 
    int i1 = getValue(); 
    int i2 = n.getValue(); 
    return i1 == i2 ? 0 : (i1 > i2 ? 1 : -1); 
  } 
} 

void keyReleased() { 
  boolean bDisplay = false; 
  if (keyCode == ENTER) { 

    bDisplay = true; 
    println(""); 
  } 
  else { 
    // Update latest number 
    Number n = (Number) numbers.get(numbers.size() - 1); 
    n.update(key); 
    print(key); 
  } 
  if (bDisplay) { 
    Collections.sort(numbers); 
    println(numbers); 
    numbers.add(new Number()); 
  }   
}
 

ooooppppsss - i never thought that this might happen to me one day
Ok, i reject non-digit chars by this if...
don't know if there is an easier way to do so......

Code:

void keyReleased() {
  if (key == 0 || key == 1 || key == 2 || key == 3 || key == 4 || key == 5 || key == 6 || key == 7 || key == 8 || key == 9){ 

**** Code is here ****
}
}