Why can't I access my variables from void Draw in void mousePressed?

Answers

• bilmor

  April 2015 Answer ✓

  You'll get better answers if you format your code with these instructions

  http://forum.processing.org/two/discussion/8045/how-to-format-code-and-text#latest
• TfGuy44

  April 2015 Answer ✓

  If you define a variable inside your draw function, that variable can only be accessed from inside your draw function!

  If you define it outside of your functions, it is global, and then can be accessed from inside all functions.

  This is known as variable scope, and it's a good topic to research if you want to learn more.

  Oh, and you have loadStrings() inside draw, Which is so blatantly wrong that I AM NOW GOING TO SHOUT AND USE BOLD TEXT BECAUSE THIS IS SUPER WRONG AND A PET PEEVE ON MINE! DO ALL YOUR LOADING IN SETUP!
• Bawchee

  April 2015

  Thanks bilmor! I've attempted to post the code again below. And thank you TfGuy44! I'm going to try your advice!

  int choice = 0;
  int randy = 0;
  long lastTime = 0;
  
  void setup() {
    size (640, 360);
    background(0);
    stroke(100);
    PFont f;
    f = createFont("Arial",16,true); // Arial, 16 point, anti-aliasing on
    noLoop();
  }
  
  void draw() {
    background(0);
  
    String factors_mult[] = loadStrings("factors_mult.txt");
    String products_mult[] = loadStrings("products_mult.txt");
  
    
    fill(255);
    textSize(width/10);
      int randy = int(random(0,factors_mult.length));
      fill(255);
      textAlign(RIGHT);
      text(factors_mult[randy],width*2/3, height/2);
      textAlign(LEFT);
      text(products_mult[randy],width*2/3, height/2);
      
      choice = int(random(2));
      println (choice);
          
      noLoop();
  }
  
  void mousePressed() {
    String factors_mult[] = loadStrings("factors_mult.txt");
    String products_mult[] = loadStrings("products_mult.txt");
  
    lastTime = millis();
    
    if (choice < 1) {
      fill(255, 0, 0);
      textAlign(RIGHT);
      text(factors_mult[randy],width*2/3, height/2);
      println (factors_mult[randy]);
      println ("Factor");
    } else {
      fill(0, 255, 0);
      textAlign(LEFT);
      text(products_mult[randy],width*2/3, height/2); 
      println (products_mult[randy]);
      println ("Product");
    }
    
    for (int i = 0; i < 10; i++) {
      i = 1;
      if (millis()-lastTime > 2000) {
        i = 10;
      }
    }
    loop();
  }
  
• Bawchee

  April 2015

  No luck yet. I'll research variable scope like you so kindly suggested, TfGuy44.
• GoToLoop

  April 2015 edited April 2015 Answer ✓

  • In Java there are basically 2 scopes: fields & local variables: ~O)
  • And curly braces create scopes. Anything declared in a scope has the lifespan of that scope!
  • Pay attention on the declare part. Declare a variable isn't the same as assign a value to it.
  • In order to declare a variable in Java, we specify its datatype at the left side of the variable's name.
  • Then we can assign values to it afterwards.
  • Watch out for re-declaration of the same variable name later on! Source of nasty bugs!

  
  

  int global_field = 10; // field or "global" variable. Exists within the sketch's class.
  
  {
    int local_block = 20; // this variable only exists within these curly braces!
  }
  
  void setup() {
    int local_method = 30; // this variable only exists within setup() method!
  
    println(global_field); // displaying the content of the sketch's field.
    println();
  
    for (int i = 0; i != 10; ++i) { // iterator i only exists within this for () loop block!
      displayVal(i);
    }
  }
  
  static final void displayVal(int val) { // parameters are also local variables!
    println(val);
  }
  
• PhiLho

  April 2015 Answer ✓

  What are setup() and draw()?

  And no point in reposting code, just edit your initial message and change it.