fix some file extensions

Task/Classes/TIScript/classes.ti

@@ -0,0 +1,35 @@
+class Car
+{
+  //Constructor function.
+  function this(brand, weight, price = 0) {
+    this.brand = brand;
+    this.weight = weight || 1000; // Resort to default value (with 'or' notation).
+    this._price = price;
+  }
+  property price(v) // computable property, special kind of member function
+  {
+    get { return this._price; } // getter section
+    set { this._price = v; }    // setter section
+  }
+  function toString() { // member function, method of a Car.
+    return String.printf("<%s>",this.brand);
+  }
+}
+
+class Truck : Car
+{
+  function this(brand, size) {
+    super(brand, 2000); // Call of constructor of super class (Car here)
+    this.size = size; // Custom property for just this object.
+  }
+}
+
+var cars = [ // Some example car objects.
+  new Car("Mazda"),
+  new Truck("Volvo", 2, 30000)
+];
+for (var (i,car) in cars) // TIScript allows enumerate indexes and values
+{
+  stdout.printf("#%d %s $%d %v %v, %v %v", i, car.brand, car.price, car.weight, car.size,
+                 car instanceof Car, car instanceof Truck);
+}