added some exercise bits to step 2.1

step2-01/README.md

@@ -1,8 +1,87 @@
 # Step 2.1
 
-Typescript
+## Introduction to Typescript
 
-- ES6 modules review
-- a look at types
-- defining interfaces
--
+In this exercise, we'll cover enough of the Typescript concepts to be productive with the React & Redux frameworks.
+
+Topics in this Exercise will include:
+
+- ES modules
+- Basic Types
+- Interfaces & Classes
+- Basic Generics
+- Spread and Destructuring
+- Async / Await
+
+## Exercise
+
+Please complete all exercises inside the `exercise/src` folder unless otherwise specified in the exercises below. First, open up [Step2-01 exercise page](http://localhost:8080/step2-01/exercise/) to see the results while you're implementing things.
+
+### Modules
+
+1. Open up file called `index.ts` in VS Code
+
+2. Create another module file called `fibonacci.ts`
+
+3. Inside the file from (step 2), write a function called `fib(n)` that takes in a number and returns a the n-th Fibonacci number - be sure the specify the type of n
+
+4. Export `fib(n)` as a **named export**
+
+5. Export another const variable as a **default export**
+
+6. Import both the modules created in steps (4) and (5) and use the provided `log()` function to log it onto the page.
+
+### Types, Interfaces, and Classes
+
+Create inside `index.ts`:
+
+1. a type alias for string union type describing the states of Red-Green-Yellow traffic light
+
+2. a class hierarchy of your favorite metaphor (e.g. family, autombiles, animals)
+
+3. describe an object type with an interface
+
+### Generic
+
+Inside `index.ts`, create a generic class for a `Stack<T>` complete with a typed `pop()` and `push()` methods
+
+Hint: the Javascript array already has `push()` and `pop()` implemented for you. That can be your backing store.
+
+Be sure to use the provided `log()` to show the functionality of `Stack<T>`
+
+### Spread and Destructure
+
+1. Note the following code in index.ts:
+
+```ts
+const obj1 = {
+  first: 'who',
+  second: 'what',
+  third: 'dunno',
+  left: 'why'
+};
+
+const obj2 = {
+  center: 'because',
+  pitcher: 'tomorrow',
+  catcher: 'today'
+};
+```
+
+2. Now create a one-liner using the spread syntax `{...x, ...y}` to create a new variable that combines these two objects.
+
+3. Using the destructuring syntax to retrieve the values for `{first, second, catcher}` from this new object created in step (2).
+
+### Async / Await
+
+1. Note the following code in index.ts:
+
+```ts
+function makePromise() {
+  return Promise.resolve(5);
+}
+```
+
+2. call `makePromise()` with the `await` syntax and log the results using the provided `log()` function
+
+3. create a new function that uses the `async` keyword to create an async function. Make an await call to `makePromise()` and return the results