Add: Class code examples

dart/lab05/README.md

@@ -5,17 +5,183 @@ Classes allow member access to specific code definitions.
 
 Return to [Dart Essentials](https://github.com/rosera/flutter_workshop/tree/main/dart)
 
-# Classes
+# Create a Class
 
- TBC
+Dart uses Classes to represent an object. 
 
 #### Use Case:
 
-* TBC 
+* You want to create a Class 
 
-#### Example: 
+#### [Example](https://github.com/rosera/flutter_workshop/blob/main/dart/lab05/solutions/hello-class.dart): 
 ```dart
-TBC 
+const numDays = 7;
+
+class DaysLeftInWeek { 
+  int currentDay = DateTime.now().weekday.toInt();
+
+  DaysLeftInWeek();
+
+  int howManyDaysLeft(){
+    return numDays - currentDay;
+  }
+}
+
+void main() {
+  var currentDay = DaysLeftInWeek();
+  
+  print ('Today is day ${currentDay.currentDay}');
+  print ('We have ${currentDay.howManyDaysLeft()} day(s) left in the week');
+}
+```
+
+# Use a Class constructor
+
+Dart uses Classes to represent an object. 
+
+#### Use Case:
+
+* You want to create a Class constructor 
+
+#### [Example](https://github.com/rosera/flutter_workshop/blob/main/dart/lab05/solutions/constructor-class.dart): 
+```dart
+const numDays = 7;
+
+class DaysLeftInWeek {
+  int currentDay = 0;
+
+  DaysLeftInWeek(){
+    currentDay = DateTime.now().weekday.toInt();
+  }
+
+  int howManyDaysLeft(){
+    return numDays - currentDay;
+  }
+}
+
+void main() {
+  var currentDay = DaysLeftInWeek();
+
+  print ('Today is day ${currentDay.currentDay}');
+  print ('We have ${currentDay.howManyDaysLeft()} day(s) left in the week');
+}
+```
+
+
+# Extending a Class
+
+Dart uses Classes to represent an object. 
+
+#### Use Case:
+
+* You want to extend a Class 
+
+#### [Example](https://github.com/rosera/flutter_workshop/blob/main/dart/lab05/solutions/extend-class.dart): 
+```dart
+class Media {
+  String title = "";
+  String type = "";
+
+  Media(){ type = "Class"; }
+
+  void setMediaTitle(String mediaTitle){ title = mediaTitle; }
+
+  String getMediaTitle(){ return title; }
+
+  String getMediaType(){ return type; }
+}
+
+class Book extends Media {
+  String author = "";
+  String isbn = "";
+
+  Book(){ type = "Subclass"; }
+
+  void setBookTitle(String bookTitle){ title = bookTitle; }
+
+  void setBookAuthor(String bookAuthor){ author = bookAuthor; }
+
+  void setBookISBN(String bookISBN){ isbn = bookISBN; }
+
+  String getBookTitle(){ return title; }
+
+  String getBookAuthor(){ return author; }
+
+  String getBookISBN(){ return isbn; }
+}
+
+void main() {
+  var myMedia = Media();
+
+  myMedia.setMediaTitle('Tron');
+  print ('Title: ${myMedia.getMediaTitle()}');
+  print ('Type: ${myMedia.getMediaType()}');
+
+
+  var myBook = Book();
+  myBook.setBookTitle("Jungle Book");
+  myBook.setBookAuthor("R Kipling");
+  print ('Title: ${myBook.getMediaTitle()}');
+  print ('Author: ${myBook.getBookAuthor()}');
+  print ('Type: ${myBook.getMediaType()}');
+}
+```
+
+
+# Extending a Class with Mixins
+
+Dart uses Classes to represent an object. 
+
+#### Use Case:
+
+* You want to extend a Class with Mixins 
+
+#### [Example](https://github.com/rosera/flutter_workshop/blob/main/dart/lab05/solutions/mixins-class.dart): 
+```dart
+abstract class SnickersOriginal {
+  bool hasHazelnut = true;
+  bool hasRice = false;
+  bool hasAlmond = false;
+}
+
+abstract class SnickersCrisp {
+  bool hasHazelnut = true;
+  bool hasRice = true;
+  bool hasAlmond = false;
+}
+
+class ChocolateBar {
+  bool hasChocolate = true;
+}
+
+class CandyBar extends ChocolateBar with SnickersOriginal {
+  List<String> ingredients = [];
+
+  CandyBar(){
+    if (hasChocolate){
+      ingredients.add('Chocolate');
+    }
+    if (hasHazelnut){
+      ingredients.add('Hazelnut');
+    }
+    if (hasRice){
+      ingredients.add('Hazelnut');
+    }
+    if (hasAlmond){
+      ingredients.add('Almonds');
+    }
+  }
+
+  List<String> getIngredients(){
+    return ingredients;
+  }
+}
+
+void main() {
+  var snickersOriginal = CandyBar();
+  print ('Ingredients:');
+  snickersOriginal.getIngredients().forEach((ingredient) => print(ingredient));
+}
 ```
 
 Return to [Dart Essentials](https://github.com/rosera/flutter_workshop/tree/main/dart)

dart/lab05/solutions/constuctor-class.dart

@@ -0,0 +1,21 @@
+
+const numDays = 7;
+
+class DaysLeftInWeek {
+  int currentDay = 0;
+
+  DaysLeftInWeek(){
+    currentDay = DateTime.now().weekday.toInt();
+  }
+
+  int howManyDaysLeft(){
+    return numDays - currentDay;
+  }
+}
+
+void main() {
+  var currentDay = DaysLeftInWeek();
+
+  print ('Today is day ${currentDay.currentDay}');
+  print ('We have ${currentDay.howManyDaysLeft()} day(s) left in the week');
+}

dart/lab05/solutions/extend-class.dart

@@ -0,0 +1,47 @@
+class Media {
+  String title = "";
+  String type = "";
+
+  Media(){ type = "Class"; }
+
+  void setMediaTitle(String mediaTitle){ title = mediaTitle; }
+
+  String getMediaTitle(){ return title; }
+
+  String getMediaType(){ return type; }
+}
+
+class Book extends Media {
+  String author = "";
+  String isbn = "";
+
+  Book(){ type = "Subclass"; }
+
+  void setBookTitle(String bookTitle){ title = bookTitle; }
+
+  void setBookAuthor(String bookAuthor){ author = bookAuthor; }
+
+  void setBookISBN(String bookISBN){ isbn = bookISBN; }
+
+  String getBookTitle(){ return title; }
+
+  String getBookAuthor(){ return author; }
+
+  String getBookISBN(){ return isbn; }
+}
+
+void main() {
+  var myMedia = Media();
+
+  myMedia.setMediaTitle('Tron');
+  print ('Title: ${myMedia.getMediaTitle()}');
+  print ('Type: ${myMedia.getMediaType()}');
+
+
+  var myBook = Book();
+  myBook.setBookTitle("Jungle Book");
+  myBook.setBookAuthor("R Kipling");
+  print ('Title: ${myBook.getMediaTitle()}');
+  print ('Author: ${myBook.getBookAuthor()}');
+  print ('Type: ${myBook.getMediaType()}');
+}

dart/lab05/solutions/hello-class.dart

@@ -1,9 +1,16 @@
-class FlutterDev {
-  FlutterDev() {
-    print('I am a Flutter Developer');
+const numDays = 7;
+
+class DaysLeftInWeek { 
+  int currentDay = DateTime.now().weekday.toInt();
+
+  int howManyDaysLeft(){
+    return numDays - currentDay;
   }
 }
 
 void main() {
-  var typeOfDeveloper = new FlutterDev();
+  var currentDay = DaysLeftInWeek();
+
+  print ('Today is day ${currentDay.currentDay}');
+  print ('We have ${currentDay.howManyDaysLeft()} day(s) left in the week');
 }

dart/lab05/solutions/mixins-class.dart

@@ -0,0 +1,44 @@
+abstract class SnickersOriginal {
+  bool hasHazelnut = true;
+  bool hasRice = false;
+  bool hasAlmond = false;
+}
+
+abstract class SnickersCrisp {
+  bool hasHazelnut = true;
+  bool hasRice = true;
+  bool hasAlmond = false;
+}
+
+class ChocolateBar {
+  bool hasChocolate = true;
+}
+
+class CandyBar extends ChocolateBar with SnickersOriginal {
+  List<String> ingredients = [];
+
+  CandyBar(){ 
+    if (hasChocolate){
+      ingredients.add('Chocolate');
+    }
+    if (hasHazelnut){
+      ingredients.add('Hazelnut');
+    }
+    if (hasRice){
+      ingredients.add('Hazelnut');
+    }
+    if (hasAlmond){
+      ingredients.add('Almonds');
+    }
+  }
+
+  List<String> getIngredients(){ 
+    return ingredients; 
+  }
+}
+
+void main() {
+  var snickersOriginal = CandyBar();
+  print ('Ingredients:');
+  snickersOriginal.getIngredients().forEach((ingredient) => print(ingredient));
+}