---
# System prepended metadata

title: Lecture 16 Setup/Prep
tags: [Setup]

---

---
tags: Setup
---

# Lecture 16 Setup/Prep

In this lecture, we will outline how to actually implement hashmaps (a task you will finish on an upcoming homework). We will also wrap up our section on model-view-controller.

## Prep

We will start in breakout groups to work through understanding the following program, both at the level of output (as a programmer) and the level of the underlying memory diagram (as a hashtable implementor).

Nothing to download; just get familiar with the code so you can discuss it in breakouts.

```
import java.util.HashMap;

HashMap<Integer,String> IDtoName = new HashMap<...>
IDtoName.put(100003, “A”);
IDtoName.put(100016, “B”);
IDtoName.put(100007, “C”);
IDtoName.put(100021, “D”);
IDtoName.put(100016, ”E”);

System.out.println(IDtoName.get(100016));
System.out.println(IDtoName.get(100003));
System.out.println(IDtoName.get(100007));

```