Jon week4

week3/homework/calculator.rb

@@ -0,0 +1,24 @@
+class Calculator
+  def sum(values)
+    values.inject(0) { |result, next_val| result + next_val }
+  end
+  def multiply(*values)
+    values_list = Array.new
+    if (values.first.kind_of?(Array))
+      values_list += values.first
+    else
+      values_list += values
+    end
+    values_list.inject { |result, next_val| result * next_val }
+  end
+
+  def pow(base, exponent)
+    result = 1
+    exponent.times{ result *= base }
+    result
+  end
+
+  def fac(value)
+    value == 0 ? 1 : (1..value).inject { |result, next_val| result * next_val }
+  end
+end

week3/homework/questions.txt

@@ -6,10 +6,24 @@ Please Read:
 
 1. What is a symbol?
 
+A: A symbol is Ruby's immutable string-like unique primative, used when creating a variable that stands for something significant, much like enumerables in other languages. An example might be creating a symbol for each direction like :up, :down, :left. :right.
+
 2. What is the difference between a symbol and a string?
 
+A: Strings are mutable, symbols are immutable. 
+
 3. What is a block and how do I call a block?
 
+A: Blocks are chunks of code inbetween delimeters, curly braces or keywords 'do' and 'end'. Blocks are called with a method name, code wrapped in the do and end keywords and any parameters passed to the block with pipes '|' on either side.
+
+method_name {|parameter| parameter.work}
+
 4. How do I pass a block to a method? What is the method signature?
 
+A: You can pass a block to a method by immediately including a block following a method name. The method signature does not have to be special, and does not have to take any special parameters. However to emit values to a block, the method definition needs to contain the yield keyword. 
+
+method_name {|parameter| parameter.work}
+
 5. Where would you use regular expressions?
+
+A: Regular expressions are used in any situation that calls for string finding/matching. Regex's can be used for user input validation, manipulation/searching of large text files, or even extraction of values from unstructured data.  

week4/homework/questions.txt

@@ -4,10 +4,28 @@ The Rake Gem: http://rake.rubyforge.org/
 
 1. How does Ruby read files?
 
+A: Call File.open on the file in the file system, and then use a block to call something on the file object iterator, typically something like the each_line method. Each line will yield a string value for line of the file. 
+
+File.open("aFile.txt") do |file|
+  file.each_line {|line| puts  line }
+end
+
 2. How would you output "Hello World!" to a file called my_output.txt?
 
+A: Call File open on my_output.txt, passing a "w" for as the mode param (write), and then call puts "Hello World!" on the resulting file object.
+
+File.open("my_output.txt" "w") do |file|
+  file.puts "Hello World!"
+end
+
 3. What is the Directory class and what is it used for?
 
+A: The directory class is a standard ruby library class that represent directories (folders) within a host machine's local file system. It provides multiple methods to enumerate directories and files within those directories. 
+
 4. What is an IO object?
 
+A: An IO object is a bidirectional channel between a Ruby program and external resources like files or sockets. Files and sockets are subclasses of the IO object and support similar interfaces. 
+
 5. What is rake and what is it used for? What is a rake task?
+
+A: Rake is a build utility that is used to provide an easy to use domain specific language to define/automate common tasks that a developer may commonly run within a ruby project. A rake task is similar to a function, you can call a particular rake task by name and it will run whatever operations defined for that task. A task example might be setting some environment variable used by a ruby program.  

week4/homework/worker.rb

@@ -0,0 +1,7 @@
+module Worker
+  def self.work(n = 1)
+    val = nil
+    n.times {val = yield}
+    return val
+  end
+end