uncaught type error in game loop

[TheCrock]

I have this slice of code which works but is throwing an error in the console.

Uncaught type error. Cannot read property of x at undefined.

I am using the game loop to move a sprite on its x and y axis. The code works but i get an error and I would be interested to know why.

Also when i try to introduce, 

let state = play; so i can change the call that requests the play(); function to state(); my code stops working. I would like to be able to change the value of state so i can change which function I call by changing the value of state variable. 

Does any wise member know where i am going wrong?

gameLoop();

function gameLoop() {

    
requestAnimationFrame(gameLoop);

    //Update the current game state:
  play();

    //Render the stage

 renderer.render(stage);
   
  }

  function play() {

    
    explorer.x += explorer.vx;
    explorer.y += explorer.vy;
  }
 

Thanks guys.

 

 

 

 

[Horizonicblue]

6 hours ago, TheCrock said:

Uncaught type error. Cannot read property of x at undefined.

I guess in this case you have not defined explorer properly, so when you do explorer.x += explorer.vx; it must be throwing error