Question

I have this ridicolously easy piece of code. It works flawlessly on Firefox and Chrome but not in IE. I’ve never debugged on IE so maybe is a well known problem.

  for (i = 0; i < word_array.length; i++) {

    word_array[i].weight = parseFloat(word_array[i].weight, 10);
  }

It says word_array is null or not an object.
word_array is an array containing objects with a weight field and a string field. If i try to print for example

word_array[0].weight 

just before this code, it works. Same for printing the index “i” and parseFloat(…).

Answer 1

Posting this as an answer as it won’t fit in a comment…

The first thing I look for in IE JavaScript problems is trailing commas in arrays or objects. For example

var word_array = [
    { weight: 1, text: "a" },
    { weight: 2, text: "b" }, // see this trailing comma here
];

This will work in non-IE browsers but fail in all sorts of ways in IE.

Also, is your “string field” actually called “string”? This may cause problems though I could be wrong.