A simple JavaScript function that gives you a way to maintain a unique list of strings, by a string key, similar in function to a c# dictionary<string, List<string>>.

stringDictionary.js

"use strict";

$.stringDictionary = function () {
    this.data = {};

    // adds a unique value to the array stored in 'key'
    this.add = function (key, value) {

        var editors = this.data[key];
        if (editors) {
            if (!this.contains(key, value)) {
                this.data[key].push(value);
            }
        } else {
            this.data[key] = new Array();
            this.data[key].push(value);
        }
    };

    // attempts to remove the value from the array in 'key'
    this.remove = function (key, value) {

        var values = this.data[key];
        var index = values.indexOf(value);

        if (index > -1) {
            values.splice(index, 1);
        }

    };

    // dumps the entire map to the console
    this.dumpFields = function () {
        console.debug(this.data);
        for (var key in this.data) {
            var values = this.data[key];
            for (var index in values) {
                var msg = key + ':' + values[index];
                console.debug(msg);
                $("#foo").append($('<p>').html(msg));
            }
        }
        console.debug('-----');
    }

    // checks to see if a value is present in the map
    this.contains = function (key, value) {
        return (this.data[key].indexOf(value) > -1);
    }

    // helper method to get the list of keys
    this.keys = function(){
        var result = new Array();
        for (var key in this.data) {
            result.push(key);
        }
        return result;
    }
    
    // clears all the data
    this.clear = function () {
        this.data = {};
    }

};