type KeyValuePair<T> = {
  Key: string;
  Value: T;
}

interface IDictionary<T>
{
  Add(key: string, value: T): boolean;
  Remove(key: string): boolean;
  ContainsKey(key: string): boolean;

  Keys: string[];
  Values: T[];
}

class Dictionary<T> implements IDictionary<T>
{
  private items: { [index: string]: T } = {};

  constructor(init?: { key: string; value: T; }[]) {
    if (init) {
      for (var x = 0; x < init.length; x++) {
        this.items[init[x].key] = init[x].value;
      }
    }
  }

  public Add(key: string, value: T): boolean {
    if (this.ContainsKey(key))
    {
      return false;
    }
    this.items[key] = value;
    return this.ContainsKey(key);
  }

  public Remove(key: string): boolean
  {
    if (this.ContainsKey(key))
    {
      delete this.items[key];
      return !this.ContainsKey(key);
    }
    return false;
  }

  public get Keys(): string[]
  {
    return Object.keys(this.items);
  }

  public get Values(): T[]
  {
    return Object.keys(this.items).map(key => this.items[key]);
  }

  public get KeyValuePairs(): KeyValuePair<T>[] {
    return Object.keys(this.items).map(key =>
      (<KeyValuePair<T>>{ Key: key, Value: this.items[key] })
    );
  }

  public ContainsKey(key: string)
  {
    if (typeof this.items[key] === "undefined") {
      return false;
    }
    return true;
  }

}
let mydic = new Dictionary<string>();
mydic.Add("siema", "lol");
mydic.Add("siema2", "lol");

let button = document.createElement('button');
button.textContent = "Say Hello";
button.onclick = function () {
  for (let item of mydic.KeyValuePairs) {
      alert(item);
  }

}

document.body.appendChild(button);