var x=200; 
var y=200; 
var speed=2; 
 
function setup() { 
 createCanvas(400, 400); 
} 
 
function draw() { 
 background(220); 
 ellipse(x,y,20,20); 
 if(keyIsPressed){ 
 //持續觸發 
 //字母用小寫 
 if(key=='a'){ 
 x-=speed; 
 } 
 if(key=='d'){ 
 x+=speed; 
 } 
 } 
 if(keyIsDown(87)){ 
 //持續觸發 
 //使用keyCode 
 //87即w 
 y-=speed; 
 } 
 if(keyIsDown(83)){ 
 //持續觸發 
 //使用keyCode 
 //83即s 
 y+=speed; 
 } 
} 
 
function keyPressed(){ 
 //按鍵按下時觸發一次 
 //字母用大寫 
 if(key=='Z'){ 
 x-=20; 
 } 
 if(key=='X'){ 
 x+=20; 
 } 
} 
 
function keyReleased(){ 
 //按鍵松開時觸發一次 
 //字母用大寫 
 if(key=='C'){ 
 y-=20; 
 } 
 if(key=='V'){ 
 y+=20; 
 } 
}

function setup() { 
 createCanvas(400, 400); 
} 
 
function draw() { 
 background(220); 
 textAlign(CENTER); 
 textSize(30); 
 if(keyIsPressed){ 
 text(key,200,180); 
 text(keyCode,200,220); 
 } 
}