Quick edits in inheritance notes.

Author: aubertc

source/code/projects/Vehicle/Vehicle/Bike.cs

@@ -5,7 +5,9 @@ public class Bike : Vehicle
   public Bike()
   {
     ForkLength = -1;
-    SetNOW(2); // or base.setNOW(2);
+    SetNOW(2); 
+    // or 
+    // base.SetNOW(2);
   }
 
   public Bike(string cP, double flP)

source/code/projects/Vehicle/Vehicle/Vehicle.cs

@@ -1,3 +1,4 @@
+using System;
 public class Vehicle
 {
   public string Color { get; set; }
@@ -9,7 +10,8 @@ public void SetNOW(int nowP)
       numberOfWheels = nowP;
     else
       numberOfWheels = -1;
-    // We could also decide to throw an exception here.
+    // We could also decide to throw an exception here, using e.g.
+    // throw new ArgumentException();
   }
 
   public Vehicle()
@@ -22,6 +24,8 @@ public Vehicle(string cP, int nowP)
   {
     Color = cP;
     numberOfWheels = nowP;
+    // We could also use our SetNOW method, as follows:
+    // SetNOW(nowP);
   }
 
   public override string ToString()

source/lectures/oop/inheritance.md

@@ -49,7 +49,7 @@ Note:
     and the `Vehicle` `Color` accessor will be used, since `Bike` does not have an accessor for `Color`.
 
 - Implicitly, the `Bike()` constructor starts by calling the `Vehicle()` constructor, so that `Color` and `numberOfWheels` are actually set to `"undefined"` and `-1`, respectively.
-- That `SetNOW` into the `Bike()` constructor actually refers to the `SetNOW` method in the `Vehicle` class. A way of being more explicit would have been to write `base.SetNOW` instead of `SetNOW`. In either case, the value `-1M` is overriden by `2` (since every bike has 2 wheels).
+- That `SetNOW` into the `Bike()` constructor actually refers to the `SetNOW` method in the `Vehicle` class. A way of being more explicit would have been to write `base.SetNOW` instead of `SetNOW`. In either case, the value `-1` is overriden by `2` (since every bike has 2 wheels).
 - The `: base(cP, 2)` instructs to call the 
 
     `Vehicle(string cP, int nowP)`