Step 2-01 updates

step2-01/demo/src/interfaces/index.ts

@@ -1,22 +1,32 @@
+// Interface for an object or class
 interface Car {
   make: string;
   model: string;
 }
 
 class MyCar implements Car {
-  make: 'Honda';
-  model: 'Accord';
-}
+  make: string;
+  model: string;
 
-const myCar: Car = {
+  constructor(make: string, model: string) {
+    this.make = make;
+    this.model = model;
+  }
+}
+const myCar1: Car = new MyCar('Honda', 'Accord');
+
+const myCar2: Car = {
   make: 'Honda',
   model: 'Accord'
 };
 
-// Interface as Functions
+// Interface for a function
 interface InterestingFn {
   (someArgs: string): number;
 }
+const interesting: InterestingFn = (someArgs: string): number => {
+  return Number(someArgs);
+};
 
 // adding an export to turn this into a "module"
 export default {};