How to mimicry an Object ({ }) to an Array ([]) with index rearranging

ObjectMimicry.js

var object = {
    1: "lorem",
    2: "ipsum",
    3: "dolor",
    4: "sit",
    5: "amet"
};

var calculateKeyPosition = function(object, key) {
    var props = Object.getOwnPropertyNames(object);
    // indexOf uses strong comparing (===) and props are always string values
    key = typeof(key) === typeof("") ? key : key.toString();
    return props.indexOf(key);
};
var rearrangeKeys = function(object, startIndexPosition) {
    var props = Object.getOwnPropertyNames(object);
    for (var i = startIndexPosition; i < props.length; i++) {
        var currentKey = parseInt(props[i]);
        var nextKey = currentKey - 1;
        var value = object[currentKey];
        delete object[currentKey];
        object[nextKey] = value;
    }
};

var key = 1;
var position = calculateKeyPosition(object, key);
if (position !== -1) {
    delete object[key];
    rearrangeKeys(object, position);
}
console.log(object);