Merge more runnable code-adjacent features (#29)

* more sections

* First feedback round

* Update prelude.md

* ...

* Spelling fix

Co-Authored-By: Firas Regaieg <[email protected]>

* Arguments chapter

* More Challenges

* Run prettier

* user input

* October 14th, #1

* Array challenges

* Delete challenges

* Null

* ...

* Update null_as_absence.md

* Delete out.json

* Fix quotes

* Add first no_runs

* Fix number example

---------

Co-authored-by: Firas Regaieg <[email protected]>

Author: bowbahdoe

README.md

@@ -6,7 +6,7 @@
 
 Book teaching how to write modern and effective Java. It is maintained by the community, anyone can contribute.
 
-Feel free to join our [discord server](https://discord.com/invite/XXFUXzK)
+Feel free to join our [discord server](https://discord.gg/together-java-272761734820003841)
 if you have any questions, or require assistance with the project. :relaxed:
 
 ## Getting started

book.toml

@@ -13,8 +13,8 @@ additional-css = ["ferris.css"]
 additional-js = ["ferris.js"]
 
 [output.html.fold]
-enable = true    # whether or not to enable section folding
-level = 0         # the depth to start folding
+enable = true # whether or not to enable section folding
+level = 0     # the depth to start folding
 
 [preprocessor.features]
 command = "python3 features.py"
@@ -29,3 +29,5 @@ java_21 = false
 [output.html.playground]
 editable = true
 
+[output.html.code.hidelines]
+java = "~"

features.py

@@ -49,9 +49,6 @@ def preprocess_section(context, section):
 
     json_input = json.load(sys.stdin)
     context, book = json_input
-    
-    with open("out.json", "w") as f:
-        json.dump(json_input, f)
 
     for section in book["sections"]:
         preprocess_section(context, section)

ferris.js

@@ -5,7 +5,7 @@ var ferrisTypes = [
     },
     {
       attr: 'panics',
-      title: 'This code panics!'
+      title: 'This code will crash!'
     },
     {
       attr: 'not_desired_behavior',

out.json

@@ -95,14 +95,17 @@
 # Control Flow I
 
 - [Branching Paths](./branching_paths.md)
+
   - [If](./branching_logic/if.md)
-  - [Else](./branching_logic/else.md)
   - [Nested Ifs](./branching_logic/nested_ifs.md)
+  - [Else](./branching_logic/else.md)
   - [Else If](./branching_logic/else_if.md)
   - [Relation to Delayed Assignment](./branching_logic/relation_to_delayed_assignment.md)
+  - [Scoped Variables](./branching_logic/scoped_variables.md)
   - [Conditional Operator](./branching_logic/conditional_operator.md)
   - [Boolean Expressions](./branching_logic/boolean_expressions.md)
   - [Challenges](./branching_logic/challenges.md)
+
 - [Loops](./loops.md)
   - [While](./loops/while.md)
   - [Endless Loops](./loops/endless_loops.md)
@@ -164,11 +167,10 @@
   - [Declaration](./methods/declaration.md)
   - [Invocation](./methods/invocation.md)
   - [Scope](./methods/scope.md)
-  - [Return](./methods/return.md)
-  - [Unreachable Statements](./methods/unreachable_statements.md)
   - [main](./methods/main.md)
   - [Challenges](./methods/challenges.md)
 - [Arguments](./arguments.md)
+
   - [Declaration](./arguments/declaration.md)
   - [Invocation with Arguments](./arguments/invocation_with_arguments.md)
   - [Reassignment](./arguments/reassignment.md)
@@ -177,22 +179,22 @@
   - [Overloading](./arguments/overloading.md)
   - [Inferred Types](./arguments/inferred_types.md)
   - [Challenges](./arguments/challenges.md)
-- [Return Values](./return_values.md)
-  - [void](./return_values/void.md)
+
+- [Return](./return_values.md)
+  - [Return Values](./return_values/return_values.md)
   - [Conversion](./return_values/conversion.md)
+  - [void](./return_values/void.md)
+  - [Unreachable Statements](./return_values/unreachable_statements.md)
   - [Pure Functions](./return_values/pure_functions.md)
   - [Impure Functions](./return_values/impure_functions.md)
 
-# User Input
-
-- [User Input](./user_input.md)
-
 # Data Types III
 
 - [Identity Types](./identity_types.md)
   - [Comparison with ==](./identity_types/comparison_with_equalsequals.md)
 - [Primitive Types](./primitive_types.md)
 - [null](./null.md)
+  - [Null as Absence](./null/null_as_absence.md)
   - [Checking for null](./null/checking_for_null.md)
   - [Field Access](./null/field_access.md)
   - [Instance Methods](./null/instance_methods.md)
@@ -205,7 +207,7 @@
   - [Unboxing Conversion](./boxed_primitives/unboxing_conversion.md)
   - [Boxing Conversion](./boxed_primitives/boxing_conversion.md)
   - [Arrays of Boxed Primitives](./boxed_primitives/arrays_of_boxed_primitives.md)
-  - [Challenges](./arguments/challenges.md)
+  - [Challenges](./boxed_primitives/challenges.md)
 - [Arrays II](./arrays_ii.md)
   - [Default Values](./arrays_ii/default_values.md)
   - [Populate Array]()

src/SUMMARY.md

@@ -32,6 +32,4 @@ This has the same use as regular final variables. If there are lots of lines
 of code where a variable might be reassigned, it can be useful to not have
 to read all that code to know that it does happen.[^opinion]
 
-[^opinion]:
-    Adding `final` to all arguments can make it harder to read the code, simply
-    because of visual noise.
+[^opinion]: Adding `final` to all arguments can make it harder to read the code, simply because of visual noise.

src/arguments/final_arguments.md

@@ -34,6 +34,4 @@ void main() {
 When there are multiple methods that have the same name but take different arguments,
 those methods are considered "overloads" of eachother[^overload]
 
-[^overload]:
-    "Overloading" in this context means when one word has more than
-    one possible meaning depending on how it is used. Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo.
+[^overload]: "Overloading" in this context means when one word has more than one possible meaning depending on how it is used. Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo.

src/arguments/overloading.md

@@ -21,6 +21,4 @@ int[] numbers = { 1, two, two + 1 }
 
 We call them array initializers because you use them to give an initial value to an array.[^pattern]
 
-[^pattern]:
-    You may be noticing a pattern. Confusing sounding names are often kinda "obvious"
-    with enough context.
+[^pattern]: You may be noticing a pattern. Confusing sounding names are often kinda "obvious" with enough context.

src/arrays/array_initializers.md

@@ -6,3 +6,78 @@ Remember the rules for this are
 - Try not to give up until you've given it a solid attempt
 
 ## Challenge 1
+
+Edit the following program so that the output is zero.
+
+```java
+void main() {
+    // Only change this line
+    String[] words = { "Sam", "I", "Am" };
+    System.out.println(array.length);
+}
+```
+
+## Challenge 2
+
+Using only `System.out.println` and array accesses,
+print `hello world` to the screen.
+
+```java
+void main() {
+    char[] letters = {
+        ' ',
+        'h',
+        'e',
+        'l',
+        'o',
+        'w',
+        'r',
+        'd'
+    };
+
+    // Your code here
+}
+```
+
+## Challenge 3
+
+Without editing either the array declaration or the loop at the bottom,
+make the output of this program `0`.
+
+```java
+void main() {
+    final int numbers = { 1, 2, 3, 4 };
+
+    // -----------
+    // YOUR CODE HERE
+
+
+    // -----------
+    int total = 0;
+    int index = 0;
+    while (index < numbers.length) {
+        total += numbers[index];
+        index += 1;
+    }
+    System.out.println(total);
+}
+```
+
+## Challenge 4
+
+Make this program output `bulbasaur` without changing anything
+above or below the marked areas.
+
+```java
+void main() {
+    char[] name = { 'b', 'u', 'l', 'b' };
+
+    // -----------
+    // YOUR CODE HERE
+
+
+    // -----------
+    char[] toPrint = name;
+    System.out.println(toPrint);
+}
+```