Fixes/improvements post-cohort51

1-JavaScript/Week3/README.md

@@ -411,7 +411,7 @@ To test your implementation with the Jest unit tests, run `npm test`. This will
 
 In this exercise we will practice using the Chrome debugger. Other browsers, such as FireFox, Edge and Safari have similar tools but the exact look and feel may be different.
 
-At the end of the `index.js` file of the exercise you will find a `quiz` object with multiple-choice questions that we would like you to complete as you follow along with the instructions below.
+At the end of the `index.js` file of the exercise you will find a `quiz` object with multiple-choice questions that we would like you to complete as you follow along with the instructions below. For each question, change the `?` in the `answer` property with the lowercase letter of the correct choice.
 
 > Read more about debuggers in general in the Study Guide: [Debuggers](https://hackyourfuture.github.io/study/#/tools/debuggers)
 >

1-JavaScript/Week3/assignment/ex5-wallet/index.js

@@ -69,13 +69,13 @@ walletJane.reportBalance();
 // eslint-disable-next-line no-unused-vars
 const quiz = {
   q1: {
-    question: 'At line 26, which variables are in the scope marked Closure?',
+    question: 'At line 24, which variables are in the scope marked Closure?',
     choices: { 
       a: 'There is no scope marked Closure', 
       b: 'cash, name', 
       c: 'amount, this, wallet'
     },
-    answer: undefined,
+    answer: '?',
   },
   q2: {
     question: 'What is in the Call Stack, from top to bottom?',
@@ -84,7 +84,7 @@ const quiz = {
       b: 'anonymous, transferInto', 
       c: 'transferInto, anonymous' 
     },
-    answer: undefined,
+    answer: '?',
   },
   q3: {
     question: 'What tooltip appears when hovering over the third debug button?',
@@ -93,7 +93,7 @@ const quiz = {
       b: 'Step out of current function', 
       c: 'Step' 
     },
-    answer: undefined,
+    answer: '?',
   },
   q4: {
     question: 'What is displayed in the console?',
@@ -102,7 +102,7 @@ const quiz = {
       b: 'Transferring € 50,00 from Jack to undefined', 
       c: 'Transferring € 50,00 from Jack to Jane' 
     },
-    answer: undefined,
+    answer: '?',
   },
   q5: {
     question: 'The owner of the wallet with insufficient funds is:',
@@ -111,6 +111,6 @@ const quiz = {
       b: 'Joe', 
       c: 'Jane' 
     },
-    answer: undefined,
+    answer: '?',
   },
 };

2-Browsers/Week1/README.md

@@ -134,90 +134,4 @@ This is what it should like:
 
 ![catwalk](../../assets/catwalk.gif)
 
-## Prep exercises
-
-Prep exercises are exercises that are a little more difficult. We will go through these exercises on Sunday, but do expect you to have already gotten a solution by then as a student will be asked to share their solution. You may have to come together as a class for some of them! You should NOT hand in these exercises, so make sure to not add it to the commit for your homework (have a look at the `git add` documentation [here](https://git-scm.com/docs/git-add) for all the options to exclude files in a commit).
-
-## Prep exercise: Conway's Game of Life
-
-**Folder**: `ex6-gameOfLife`
-
-In this exercise you will work with existing, working code for which you are asked to implement an enhancement. The application is a JavaScript version of a classic simulation, called [Conway's Game of Life](https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life).
-
-From Wikipedia:
-
-> The Game of Life, also known simply as Life, is a cellular automaton devised by the British mathematician John Horton Conway in 1970. It is a zero-player game, meaning that its evolution is determined by its initial state, requiring no further input. One interacts with the Game of Life by creating an initial configuration and observing how it evolves.
-
-As illustrated in the picture below, the game is a two-dimensional grid where cells come alive and die, depending on certain rules. These rules as summarized in the Wikipedia article as follow:
-
-1. Any live cell with two or three live neighbors survives.
-2. Any dead cell with three live neighbors becomes a live cell.
-3. All other live cells die in the next generation. Similarly, all other dead cells stay dead.
-
-In the exercise code a new generation of cells replaces the previous one every 200ms. For each cell of the new generation life or death is determined by applying the above rules on the state of that same cell in the current generation.
-
-![Game of Life changing](../../assets/game-of-life-1.gif)
-
-### Code walk-through
-
-<!--prettier-ignore-->
-| Function | Description |
-|----------|-------------|
-| `createCell()` | Creates a JavaScript object representing a cell with `x` (column number) and `y` (row number) properties and a boolean `aLive` property that is randomly initialized to `true` or `false`. |
-| `createGame()` | Creates the game "engine". When the function returns, its inner functions retain access to its parameters and the local `grid` variable through a closure. |
-| `createGrid()` | Creates a two-dimensional array (i.e., an array of arrays) that represents a grid of cells that evolve over time. |
-| `forEachCell()` | A higher-order function that takes a callback as its parameter. The callback is called for each cell in the two-dimensional grid array. |
-| `drawCell()` | Takes a cell object as a parameter and draws the cell on the canvas. The visual representation depends on whether the cell is alive or dead. |
-| `isAlive()` | Determines whether a cell at the given coordinates is alive or dead. The coordinates could potentially be off-grid. Off-grid cells are presumed dead. The function returns one if the given cell is alive or zero if its dead. |
-| `countLivingNeighbors()` | Counts the number of living neighbors for a given cell. Each cell has eight neighbors, some of which may be off-grid if the cell is located at an edge or a corner of the grid. |
-| `updateGrid()` | Iterates through all cells of the grid and computes the new state of each cell by applying the rules of the Game Of Life. |
-| `renderGrid()` | Iterates through all cells of the grid and draws each cell onto the canvas. |
-| `gameLoop()` | Executes one life cycle of the game (i.e., `updateGrid()` followed by `renderGrid()`) and then reschedules itself to run again after a delay. |
-| `main()` | Resizes the canvas to the desired size and then creates and starts the game engine. The function `main()` itself is executed when the browser has finished loading the page. |
-
-The diagram below visualizes the overall call hierarchy of the various functions. The `main()` function calls `createGame()`, which in turn creates a closure enclosing the `grid` array and a couple of functions that operate on that `grid`. Then, `main()` calls the `start()` function to start the game.
-
-The `start()` function creates the initial grid, renders it to the web page by calling `renderGrid()` and calls `gameLoop()` to kickstart the game.
-
-The `gameLoop()` function calls `updateGrid()` to update (each cell of) the grid according to the game rules (see above) and the calls `renderGrid()` to render the updated grid to the web page. It then schedules a call to itself using `setTimeout()`. This causes the game to keep evolving the grid according to the game rules every 200ms until the page is closed.
-
-Note: The use of [`window.requestAnimationFrame()`](https://developer.mozilla.org/en-US/docs/Web/API/window/requestAnimationFrame) is not essential for the functioning of the game but helps to avoid screen flicker.
-
-![Game of Life Call Graph](../../assets/game-of-life-call-graph.png)
-
-### Exercise
-
-In the supplied JavaScript code the color of all living cells is a single shade of blue. This is in contrast to the illustration above where living cells have different shades of blue, depending on their life time. Your job is as follows:
-
-1. In function `createCell()`, add a numeric `lifeTime` property to the object and assign it the value of one if the cell is initially alive or zero if it is initially dead.
-
-2. In function `drawCell()`, replace [`rgb()`](<https://developer.mozilla.org/en-US/docs/Web/CSS/color_value/rgb()>) with [`rgba()`](<https://developer.mozilla.org/en-US/docs/Web/CSS/color_value/rgba()>) that adds a fourth parameter indicating `opacity` to the `rgb` value like this:
-
-   ```js
-   context.fillStyle = `rgba(24, 215, 236, ${opacity})`;
-   ```
-
-   The `opacity` of each rendered cell should depend on the cell's `lifeTime` property, as specified in this table:
-
-   | lifeTime | opacity |
-   | :------: | :-----: |
-   |    1     |  0.25   |
-   |    2     |   0.5   |
-   |    3     |  0.75   |
-   |    4+    |    1    |
-
-3. In function `updateGrid()` add code to update the `lifeTime` value of each cell:
-
-   - A living cell that remains living should have its `lifeTime` incremented by one.
-   - A living cell that dies should have its `lifeTime` reset to zero.
-   - A dead cell that is brought to life should have its `lifeTime` reset to one.
-
-Here is a visual check that you can use to verify that the life time enhancement is correctly implemented. Most of the time, if you wait long enough, the game will "stabilize" to "still life" and "oscillator" patterns, as shown in the GIF below (see the Wikipedia article for more information about the Game Of Life patterns).
-
-![Game of Life stable](../../assets/game-of-life-2.gif)
-
-- Cells in a still life pattern remain living indefinitely and should therefore stabilize at the highest opacity.
-
-- The oscillating parts of an oscillator pattern continually switch between life and death and, when briefly living, should have the lowest opacity. The stable parts should be at the highest opacity.
-
 _Have fun!_