Is it possible to store integers as keys in a javascript object?

I am creating an index file in JSON, which I use as the database sort index for the javascript application I'm working on.

My index will look like this:

{
"_id": "acomplex_indices.json",
"indexAB": {
    "title": {
        "Shawshank Redemption": [
            "0"
        ],
        "Godfather": [
            "1"
        ],
        "Godfather 2": [
            "2"
        ],
        "Pulp Fiction": [
            "3"
        ],
        "The Good, The Bad and The Ugly": [
            "4"
        ],
        "12 Angry Men": [
            "5"
        ],
        "The Dark Knight": [
            "6"
        ],
        "Schindlers List": [
            "7"
        ],
        "Lord of the Rings - Return of the King": [
            "8"
        ],
        "Fight Club": [
            "9"
        ],
        "Star Wars Episode V": [
            "10"
        ],
        "Lord Of the Rings - Fellowship of the Ring": [
            "11"
        ],
        "One flew over the Cuckoo Nest": [
            "12"
        ],
        "Inception": [
            "13"
        ],
        "Godfellas": [
            "14"
        ]
    },
    "year": {
        "1994": [
            "0",
            "3"
        ],
        "1972": [
            "1"
        ],
        "1974": [
            "2"
        ],
        "1966": [
            "4"
        ],
        "1957": [
            "5"
        ],
        "2008": [
            "6"
        ],
        "1993": [
            "7"
        ],
        "2003": [
            "8"
        ],
        "1999": [
            "9"
        ],
        "1980": [
            "10"
        ],
        "2001": [
            "11"
        ],
        "1975": [
            "12"
        ],
        "2010": [
            "13"
        ],
        "1990": [
            "14"
        ]
    }
}
}

So, for each keyword(e.g. Pulp Fiction) I keep matching document-id(s).

My problem is with integers / numbers / non-string data such as the year of release in the above example. This is saved as a string, while I was hoping it would be saved as a number.

I create index entries like this:

// indices = the current index file
// doc = the document to update the index with
// priv.indices = all indices defined for this application instance
// priv.indices.fields = index fields e.g. "year", "director", "title"
// priv.indices.name = name of this index

priv.updateIndices = function (indices, doc) {
var i, j, index, value, label, key, l = priv.indices.length;

// loop all indices to add document
for (i = 0; i < l; i += 1) {
  index = {};
  index.reference = priv.indices[i];
  index.reference_size = index.reference.fields.length;
  index.current = indices[index.reference.name];

  for (j = 0; j < index.reference_size; j += 1) {
    label = index.reference.fields[j];    // like "year"
    value = doc[label];                   // like 1985

    // if document has a label field (e.g. doc.year = 1985)
    if (value !== undefined) {

      // check if the index file already contains an entry for 1985
      index.current_size = priv.getObjectSize(index.current[label]);

      if (index.current_size > 0) {
        // check if the document id is already in the index
        // in case the data is updated (e.g. change 1982 to 1985)
        key = priv.searchIndexByValue(
          index.current[label],
          doc._id,
          "key"
        );
        if (!!key) {
          delete index.current[label][key];
        }
      }
      // create a new array if 1985 is not in the index yet
      if (index.current[label][value] === undefined) {
        index.current[label][value] = [];
      }
      // add the document id to an existing entry
      index.current[label][value].push(doc._id);
    }
  }
}
return indices;

};

This works great, except that the fields that I want to keep as non-line (integers, numbers or dates and times), like the year in the above example, end up as strings in my index.

:
"" JSON? , / "non-string".

, , , , , ?

!