Q:

remove placeholder attribute on focus in plain JS (non-jQuery)

I would simply like to remove the attribute with my if condition and add it back with my else.
function onFocusChange () { 
  if (document.getElementById("input").focus()) { 
     document.getElementById("input").placeholder = "";
   else { 
     document.getElementById("input").placeholder = "This is Placeholder Text";   
   }
  }
}

mark-up:
<label for="input">
  Question #1:
</label>
<input type="text" id="input" name="Address" required="required" placeholder="This is Placeholder Text" />

A:

You can use focus & blur event

var element = document.getElementById('input');
element.addEventListener('focus', function() {
  element.setAttribute('placeholder', '')

})

element.addEventListener('blur', function() {
  element.setAttribute('placeholder', 'This is Placeholder Text')

})
<label for="input">
  Question #1:
</label>
<input type="text" id="input" name="Address" required="required" placeholder="This is Placeholder Text" />

