a port of the Processing Visualization Language


Boolean data is one bit of information. True or false. It is common to use Booleans with control statements to determine the flow of a program. In this example, when the boolean value "x" is true, vertical black lines are drawn and when the boolean value "x" is false, horizontal gray lines are drawn.

Original Processing.org Example: TrueFalse

// All Examples Written by Casey Reas and Ben Fry

// unless otherwise stated.

boolean x = false;

size(200, 200);



for (int i = 1; i < width; i += 2) 


  if (i < width/2) {

    x = true;

  } else {

    x = false;



  if (x) {


    line(i, 1, i, height-1);



  if (!x) {


    line(width/2 , i, width-2, i);


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