Why does this code print "0" for the variable dwidth?

1. void setup () {
     size(1900, 1020);
     background(0);
   }
   
   int dwidth = width;
   
   void draw() {
     println(dwidth);
   }
   

I am trying to check if a string matches the condition of having between 1-4 digits followed by a comma and 1-4 digits, for example: 0,0 = true, 1234,6 = true, 0,0, = false.

1. if (myString.matches("\\d{1,4},\\d{1,4}")) {
       trimmedString = trim(myString);
     }
     else {
       trimmedString = "0";
       println("Bad data detected: "+myString);
     }

this code always seems to output Bad data detected: myString. even when the values should be valid, like 0,0. Thanks for any help.

I keep getting a NumberFormatException, I think due to garbage data from the arduino every once in a while, but it also seems to cause a NullPointerException, for which I have no explanation. The code runs successfully for a while, until it gets some bad data. Sometimes even seemingly good data will cause it to crash. I can't seem to figure out how to catch this thing properly to keep it from crashing. Please help?

1. // Processing code for this example
   
   // Graphing sketch
   
   
   // This program takes ASCII-encoded strings
   // from the serial port at 9600 baud and graphs them. It expects values in the
   // range 0 to 1023, followed by a newline, or newline and carriage return
   
   // Created 20 Apr 2005
   // Updated 18 Jan 2008
   // by Tom Igoe
   // This example code is in the public domain.
   
   import processing.serial.*;
   
   Serial myPort;        // The serial port
   int xPos = 1;         // horizontal position of the graph
   
   void setup () {
     // set the window size:
     size(1900, 1020);       
   
     // List all the available serial ports
     println(Serial.list());
     // I know that the first port in the serial list on my mac
     // is always my  Arduino, so I open Serial.list()[0].
     // Open whatever port is the one you're using.
     myPort = new Serial(this, Serial.list()[0], 9600);
     // don't generate a serialEvent() unless you get a newline character:
     myPort.bufferUntil('\n');
     // set inital background:
     background(0);
   }
   float inByte = 0;
   float[] inByteA = new float[2];
   int[] inInt = new int[2];
   String[] inString = new String[2];
   int x = 0;
   int y = 0;
   
   void draw () {
     // everything happens in the serialEvent()
   }
   
   void serialEvent (Serial myPort) {
     // get the ASCII string:
     String trimmedString = trim(myPort.readStringUntil('\n'));
     try {
       inString = splitTokens(trimmedString, ",");
     }
     catch (Exception e) {
       println("dumbass: "+e);
       delay(2000);
     }
     //println(inString[1]);
     // print(":");
     // println(inString[1]);
   
     for (int i = 0; i < inString.length; i++) {
       if (inString[i] != null) {
   
         // convert to an int and map to the screen height:
         try {
           inByte = float(inString[i]);
         }
         catch (NumberFormatException excp) {
           inByte = 0;
           println("fucking: "+excp);
         }
         inByteA[i] = map(inByte, 0, 1023, 0, height);
         String temp = inString[i];
         println(temp);
         try {
           inInt[i] = Integer.parseInt(temp);
         }
         catch (Exception e) {
           println("goddamn: "+e);
           inInt[i]=0;
           println("i: "+i);
         }
         finally {}
        
         if (inInt[i]>=1) {
           print(i);
           print(":");
           println(inInt[i]);
         }
       }
     }
     // at the edge of the screen, go back to the beginning:
     if (xPos >= width) {
       xPos = 0;
       background(0);
     }
     else if (inInt[0]!=0 || inInt[1]!=0) {
       // draw the line:
       stroke(127, 34, 255);
       line(xPos, height/2, xPos, height/2 - inByteA[0]);
       stroke(216, 24, 24);
       line(xPos, height/2, xPos, height/2 + inByteA[1]);
   
       // increment the horizontal position:
       xPos++;
     }
   }