Code Stuff

Author: bowbahdoe

src/SUMMARY.md

@@ -261,10 +261,6 @@ enshittification state machine example (Acquire -> Make good for business bad fo
   - [Drawing Isosceles Triangles](./loops_ii/drawing_isosceles_triangles.md)
   - [Challenges](./loops_ii/challenges.md)
 
-# Projects
-
-- [ASCII Art Generator](./projects/ascii_art.md)
-
 # Code Structure
 
 - [Methods](./methods.md)
@@ -294,8 +290,27 @@ enshittification state machine example (Acquire -> Make good for business bad fo
   - [Unreachable Statements](./return_values/unreachable_statements.md)
   - [Challenges](./return_values/challenges.md)
 
+
 # Data Types III
 
+- [Multi-Dimensional Arrays](./multi_dimensional_arrays.md)
+  - [Declaration](./multi_dimensional_arrays/declaration.md)
+  - [Array Initializers](./multi_dimensional_arrays/array_initializers.md)
+  - [Initialization with new](./multi_dimensional_arrays/initialization_with_new.md)
+  - [Access Individual Elements](./multi_dimensional_arrays/access_individual_elements.md)
+  - [Set Individual Elements](./multi_dimensional_arrays/set_individual_elements.md)
+  - [Initialization with Size](./multi_dimensional_arrays/initialize_with_size.md)
+  - [Default Values](./multi_dimensional_arrays/default_values.md)
+  - [Populate Values](./multi_dimensional_arrays/populate_values.md)
+  - [Ragged Arrays](./multi_dimensional_arrays/ragged_arrays.md)
+  - [Challenges](./multi_dimensional_arrays/challenges.md)
+
+# Projects
+
+- [ASCII Art Generator](./projects/ascii_art.md)
+
+# Data Types IV
+
 - [null](./null.md)
   - [Null as Absence](./null/null_as_absence.md)
   - [Null as Unknown](./null/null_as_unknown.md)
@@ -353,7 +368,7 @@ enshittification state machine example (Acquire -> Make good for business bad fo
 - [Point of Sale System](./projects/point_of_sale_system.md)
 
 
-# Data Types IV
+# Data Types V
 
 - [Enums](./enums.md)
   - [Declaration](./enums/declaration.md)
@@ -562,7 +577,7 @@ enshittification state machine example (Acquire -> Make good for business bad fo
   - [Reverse Domain Name Notation](./packages/reverse_domain_name_notation.md)
   - [Challenges](./packages/challenges.md)
 
-# Data Types IV
+# Data Types VI
 
 - [Records](./records.md)
   - [Declaration](./records/declaration.md)
@@ -640,7 +655,7 @@ enshittification state machine example (Acquire -> Make good for business bad fo
   - [Subtypes](./interfaces/subtypes.md)
   - [Multiple Implementations](./interfaces/multiple_implementations.md)
   - [Challenges](./interfaces/challenges.md)
-# Data Types V
+# Data Types VII
 
 <!-- Note: Put a joke about the "A train leaves chicago at ..." problems.
 Make them do one. -->
@@ -730,7 +745,7 @@ Make them do one. -->
   - [Information Hiding](./encapsulation/information_hiding.md)
 
 
-# Data Types VI
+# Data Types VIII
 
 - [Collections](./collections.md)
   - [List](./collections/list.md)
@@ -743,18 +758,6 @@ Make them do one. -->
   - [Challenges](./collections/challenges.md)
 
 
-- [Multi-Dimensional Arrays](./multi_dimensional_arrays.md)
-  - [Declaration](./multi_dimensional_arrays/declaration.md)
-  - [Array Initializers](./multi_dimensional_arrays/array_initializers.md)
-  - [Initialization with new](./multi_dimensional_arrays/initialization_with_new.md)
-  - [Access Individual Elements](./multi_dimensional_arrays/access_individual_elements.md)
-  - [Set Individual Elements](./multi_dimensional_arrays/set_individual_elements.md)
-  - [Initialization with Size](./multi_dimensional_arrays/initialize_with_size.md)
-  - [Default Values](./multi_dimensional_arrays/default_values.md)
-  - [Populate Values](./multi_dimensional_arrays/populate_values.md)
-  - [Ragged Arrays](./multi_dimensional_arrays/ragged_arrays.md)
-  - [Challenges](./multi_dimensional_arrays/challenges.md)
-
 # Metaprogramming
 
 - [Reflection](./reflection.md)
@@ -812,7 +815,7 @@ Make them do one. -->
   - [Final Classes](./class_extension/final_classes.md)
 
 
-# Data Types VII
+# Data Types IX
 
 - [Niche Numerics](./niche_numerics.md)
   - [byte](./niche_numerics/byte.md)

src/multi_dimensional_arrays/challenges.md

@@ -1 +1,101 @@
 # Challenges
+
+Remember the rules for this are
+
+- Try to use only the information given up to this point in this book.
+- Try not to give up until you've given it a solid attempt
+
+
+
+
+## Challenge 1.
+
+Initialize 10x10 2D array of `int`s by size.
+Print every element of this new 2D array.
+
+Will any elements of the outermost array be `null`? 
+Write down your guess before making the program.
+
+```java,editable
+void main() {
+    int[][] xs = /* CODE HERE */
+    // CODE HERE
+}
+```
+
+## Challenge 2.
+
+Print out every character in the 2D array of `char`s. After each
+row print a new line.
+
+```java,editable
+void main() {
+    char[][] picture = new char[][] {
+        new char[] { ' ', ' ', ' ', ' ' },
+        new char[] { ' ', '*', '*', ' ' }
+        new char[] { '\\', ' ', ' ', '/' }
+        new char[] { ' ', '-', '-', ' ' }
+    };
+
+    // CODE HERE
+}
+```
+
+## Challenge 3.
+
+"Draw" a smiley face on the "canvas" provided by a 5x5 2D `char` array.
+
+Use similar code as the previous challenge to print it out.
+
+```java,editable
+void main() {
+    final char[][] picture = new char[5][5];
+
+    // CODE HERE
+}
+```
+
+
+
+## Challenge 3.
+
+Write a method named `winner`. It should take in a 2-dimensional
+array of `String`s where each character is either `X`, `O`, or an empty string.
+This 2D array represents a [game of Tic-Tac-Toe](https://en.wikipedia.org/wiki/Tic-tac-toe).
+
+If there is a winner of the Tic-Tac-Toe game, it should return `X` or `O` depending on who the winner is.
+It should return `null` if nobody won or the game is a tie.
+
+```java
+String winner(String[][] ticTacToe) {
+    // CODE HERE
+}
+
+void main() {
+    var winnerA = winner(new String[][] {
+        new String[] { "X", "X", "" },
+        new String[] { "O", "", "" },
+        new String[] { "O", "", "" }
+    });
+
+    IO.println(winnerA);
+
+    var winnerB = winner(new String[][] {
+        new String[] { "X", "X", "X" },
+        new String[] { "O", "O", "X" },
+        new String[] { "O", "", "O" }
+    });
+
+    IO.println(winnerB);
+
+    var winnerC = winner(new Character[][] {
+        new Character[] { "O", "X", "O" },
+        new Character[] { "O", "O", "X" },
+        new Character[] { "O", "X", "O" }
+    });
+
+    IO.println(winnerC);
+}
+```
+
+