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JavaScript

Posted by mryoung
mryoung
4,156 Points

Switch Method (undefined being thrown)

Here I have a button I'm grabbing from the DOM, and I'm using a click event function that fires a switch to switch between states. The result should move a div around the screen, but nothing happens.

When i open the console I simply see:

undefined

What am I not defining here?

var stateLocation = 0;


document.getElementsByClassName('button')[0].addEventListener('click',function(){
  document.getElementsByClassName('box')[0]

  switch(stateLocation){
    case 0:
  if(box.classList.contains('three')){
    box.classList.remove('three');
  };
      stateLocation = 1;
      break;

    case 1:
      document.getElementsByClassName('box')[0].classList.add('one');
      stateLocation = 2;
      break;
    case 2:
      document.getElementsByClassName('box')[0].classList.remove('one');
      document.getElementsByClassName('box')[0].classList.add('two');
      stateLocation = 3;
      break;
      case 3:
      document.getElementsByClassName('box')[0].classList.remove('two');
      document.getElementsByClassName('box')[0].classList.add('three');
      stateLocation = 0;
      break;
  }

});

1 Answer

Sean T. Unwin
Sean T. Unwin
28,690 Points

There is no assignment to a box variable.

The first line in the click handler should be refactored to:

var box = document.getElementsByClassName('box')[0];