sort a dictionary (or whatever key-value data structure in js) on word_number keys efficiently

Question

how do I sort a dictionary by key like

dict["word_21"] = "Hello Java";
dict["word_22"] = "Hello World";
dict["word_11"] = "Hello Javascript";

so that I get

dict["word_22"] = "Hello World";
dict["word_21"] = "Hello Java";
dict["word_11"] = "Hello Javascript";

There are word_number combinations on indices only and the values are strings. The indices are distinct (no equal values) but could be "undefined" in an error case

Edit: Actually I need the descending and ascending order of it. But the descending order is what I need at the moment.

Answer 1

A javascript object, here used as a key-value-map (called "dictionary"), has no order; ie. you can't sort it.

You would need an array for that, e.g.

[
    {id: "word_11", entry:"Hello Javascript"},
    {id: "word_21", entry:"Hello Java"},
    {id: "word_22", entry:"Hello World"},
]

then you could sort that by id or by entry. You might use your id-sort-algorithm for that.

---

Or you could use an array of your keys to sort, next to the unsorted data structure. This might be the best (efficient) and simplest approach:

var dict = {
    "word_21": "Hello Java",
    "word_22": "Hello World",
    "word_11": "Hello Javascript"
}; // init (like your example)

var keys = Object.keys(dict); // or loop over the object to get the array
// keys will be in any order
keys.sort(); // maybe use custom sort, to change direction use .reverse()
// keys now will be in wanted order

for (var i=0; i<keys.length; i++) { // now lets iterate in sort order
    var key = keys[i];
    var value = dict[key];
    /* do something with key & value here */
}