​

​

// you seen that you need a relational operator with some sport of 

//boolean expression because something like mouseX>100 evaluates

//to true or false. A variable with type boolean, you dont need to 

//check anything about it. it itself has the value true or false

​

// if(kyo){

 //   kyo =false ;

//} else{

  //  kyo= true;

// }

​

// what this code syas is on is true, on should be false , otherweise

//on should be true

// if its on, turn it off, otherwise it must have been off so turn if

//on

// so now you have a switch that can change the state of the program

// this can be condensed into one line of code using the 

// not operator: !

​

//if(!on) {do something} . so i have a variable on = false 

//does this code get executed?

// not false is true so !on evaluates to true 

​

// on = !on . what does that mean? i want to set the value of this 

// variable to not itself, so its value is false, not false is true

//if its value is true, not true is false 

// this expressoin reverses a boolean expression, makes true false

//false true 

var kyo = false;

function setup() {

  createCanvas(600, 400);

}

​

function draw() {

  if(kyo){

    background(0,255,0);

  } else{

  background(0);

  }

 stroke(255);

  strokeWeight(4);

  noFill();

if(mouseX>250 && mouseX< 350 &&  mouseY>150 && mouseY<250){

   fill(255,0,200);

}

  rectMode(CENTER);

  rect(300,200,100,100);

}

​

function mousePressed(){

  if(mouseX>250 && mouseX< 350 &&  mouseY>150 && mouseY<250){

  kyo=!kyo;

  }

}

​

// when you see lines in your code taht are pretty much identical,

// you should ask yourself, is there a better way to do this?

 // if(mouseIsPressed){

 //   background(0,255,0);

 // }

//