Typescript Dictionary

Dictionary.ts

//http://stackoverflow.com/questions/15877362/declare-and-initialize-a-dictionary-in-typescript

interface IDictionary {
    add(key: string, value: any): void;
    remove(key: string): void;
    containsKey(key: string): bool;
    keys(): string[];
    values(): any[];
}

class Dictionary {

    _keys: string[] = new string[];
    _values: any[] = new any[];

    constructor(init: { key: string; value: any; }[]) {

        for (var x = 0; x < init.length; x++) {
            this[init[x].key] = init[x].value;
            this._keys.push(init[x].key);
            this._values.push(init[x].value);
        }
    }

    add(key: string, value: any) {
        this[key] = value;
        this._keys.push(key);
        this._values.push(value);
    }

    remove(key: string) {
        var index = this._keys.indexOf(key, 0);
        this._keys.splice(index, 1);
        this._values.splice(index, 1);

        delete this[key];
    }

    keys(): string[] {
        return this._keys;
    }

    values(): any[] {
        return this._values;
    }

    containsKey(key: string) {
        if (typeof this[key] === "undefined") {
            return false;
        }

        return true;
    }

    toLookup(): IDictionary {
        return this;
    }
}


// EXAMPLE

var persons = new PersonDictionary([
    { key: "p1", value: { firstName: "F1", lastName: "L2" } },
    { key: "p2", value: { firstName: "F2", lastName: "L2" } },
    { key: "p3", value: { firstName: "F3", lastName: "L3" } }
]).toLookup();


alert(persons["p1"].firstName + " " + persons["p1"].lastName);
// alert: F1 L2

persons.remove("p2");

if (!persons.containsKey("p2")) {
    alert("Key no longer exists");
    // alert: Key no longer exists
}

alert(persons.keys().join(", "));
// alert: p1, p3

Thanks a lot