How to correctly use JavaScript indexOf in a date array

Question

Here is the code:

var collection = [new Date(2014, 11, 25), new Date(2014, 11, 24)];
var d=new Date(2014, 11, 24);

var idx= collection.indexOf(d);

Answer 1

indexOf() won't work here... It's been well explained in the previous answers...

You'd be able to create your own lookup for the index. Here's a simple example comparing the dates using their .getTime() value...

(function() {

  var collection = [new Date(2014, 11, 25), new Date(2014, 11, 24)];
  var d = new Date(2014, 11, 24);

  var idx1 = -1;
  collection.forEach(function(item, index){
    if(d.getTime() == item.getTime())
      idx1 = index;
  });

  var intArray = [1, 3, 4, 5];
  var idx2 = intArray.indexOf(4);

  $('#btnTry1').on('click', function() {
    $('#result1').val(idx1);
  });

  $('#btnTry2').on('click', function() {
    $('#result2').val(idx2);
  });
})();

Index:

Find index in a date array

Index:

Find index in a regular array