Question

Is there any execution speed advantage to condense individual elements into an array as below and then call e instead of document.get….? Other than shorten the loading time of the script. TIA.

FROM

document.getElementById('id1')
document.getElementById('id2')
document.getElementById('id3')

TO

var e=document.getElementById("id1","id2","id3"); 

edit: I mean getElementById, not some specialized tags.

Answer 1

Two ways to do this could be:

//return an array of elements
function elementsById(ids){
  var idsget = [].slice.call(arguments), result = [];
  for (var i=0;i<idsget.length;i=i+1){
    result.push(document.getElementById(idsget[i]);
  }
  return result;
}
var els = elementsById('id1','id2','id3');
// retrieve using els[0], els[1] etc.

// return an object
function elementsById(ids){
  var idsget = [].slice.call(arguments), result = {};
  for (var i=0;i<idsget.length;i=i+1){
    result[idsget[i]] = document.getElementById(idsget[i]);
  }
  return result;
}
var els = elementsById('id1','id2','id3');
// retrieve using els.id1, els.id2 etc.

It won’t gain speed initially (document.getElementById is called as many times as it would be referencing the elements without a storage function), but will be more efficient if you subsequently need the elements in the remainder of your script.