Multi-Key With Graphics

boolean[] keys;
int x = 200, y = 200;

void setup()
{
  size(600, 600);
  keys=new boolean[4];
}

void draw() 
{
  background(255);
  if( keys[0]) 
    x -= 3;
  if( keys[1]) 
    y -= 3;
  if (keys[2])
    x += 3;
  if (keys[3])
    y += 3;
  ellipse(x, y, 20,20);
}

void keyPressed()
{
  if(key == CODED)
  {
    if (keyCode == LEFT)
      keys[0]=true;
    if(keyCode==UP)
      keys[1]=true;
    if (keyCode == RIGHT)
      keys[2] = true;
    if (keyCode == DOWN)
      keys[3] = true;
  }
}

void keyReleased()
{
  if(key == CODED)
  {
    if (keyCode == LEFT)
      keys[0]=false;
    if(keyCode==UP)
      keys[1]=false;
    if (keyCode == RIGHT)
      keys[2] = false;
    if (keyCode == DOWN)
      keys[3] = false;
  }
}