Question

I need help with a loop… it’s probably simple but I’m having difficulty coding it up.

Basically, I need to check existing Ids for their number so I can create a unique id with a different number. They’re named like this: id=”poly’+i'” in sequence with my function where i is equal to the number of existing elements. Example: Array 1, Array 2, Array 3 corresponding with i=1 for the creation of Array 1, i=2 for Array 2, etc.

Right now i is based on the total number of existing elements, and my “CreateNew” function is driven off x=i+1 (so the example above, the new element will be named Array 4). The problem is that if you delete one of the middle numbers, the “Create” function will duplicate the high number. i.e. Array 1, 2, 3 delete 2, create new-> Array 1, 3, 3.

I need an if() statement to check if the array already exists then a for() loop to cycle through all i’s until it validates. Not sure how to code this up.

The code I’m trying to correct is below (note I did not write this originally, I’m simply trying to correct it with my minimal JS skills):

function NewPanel() {


  var i = numberOfPanels.toString();
  var x = (parseInt(i)+1).toString(); 


  $('#items').append('<div onclick="polygonNameSelected(event)" class="polygonName" id="poly'+i+'">&nbsp;&nbsp;Array '+ x +' &nbsp;&nbsp;&nbsp;&nbsp;<a href="javascript:void(0)" onclick="removePolygon('+i+');return false;">&nbsp;&nbsp;&nbsp;</a></div>');
  $('div[id*=poly]').removeClass('selected');
  $('#poly'+i).addClass('selected');
  $('#poly'+i).click(function() {
    selectedPolygon = i;
    $('div[id*=poly]').removeClass('selected');
    $(this).addClass('selected');
  });

}

THANK YOU! 🙂

Answer 1

Please clarify “The problem is that if you delete one of the middle numbers, “. What do you mean by delete? Anyway, the simplest solution is to create two arrays. Both arrays will have the same created id’s. Whenever an id is created in the first array, an id will be added to the second array. So when it is deleted from first array, check your second array’s highest value and then create this id in first array. I hope this did not confuse you.