Week 3 homework

week1/homework/questions.txt

@@ -3,13 +3,29 @@ Chapter 3 Classes, Objects, and Variables
 p.86-90 Strings (Strings section in Chapter 6 Standard Types)
 
 1. What is an object?
+An object represents data that can be manipulated.
 
 2. What is a variable?
+A reference to an object. They are used to keep track of objects.
 
 3. What is the difference between an object and a class?
+A class is each named thing that the code needs to find answers or do
+work.
+(ie a User class that represents all the users about whom I collect
+information. A class does not change.
+Information that the class represents can change ). An object
+represents data within the class that can be changed.
+The user object is used when I collect data about my users.
 
 4. What is a String?
+objects of class String. They can hold printable characters or binary data.
 
-5. What are three messages that I can send to a string object? Hint: think methods
+5. What are three messages that I can send to a string object? Hint:
+   think methods
+   Chomp, Split, Squeeze
 
 6. What are two ways of defining a String literal? Bonus: What is the difference between them?
+double quotes, single quotes. Double quoted strings support more
+escape sequences. I think this is because everything between single
+quotes in interpreted literally - so \n would print \n if it's between
+single quotes.

week1/homework/strings_and_rspec_spec.rb

@@ -1,7 +1,9 @@
+# encoding: utf-8
+
 require 'rspec/collection_matchers'
 require_relative '../../spec_helper'
 
-# encoding: utf-8
+
 
 # Please make these examples all pass
 # You will need to change the 3 pending tests
@@ -11,24 +13,31 @@
 # 	(Hint: You should do the reading on Strings first)
 
 describe String do
-	context "When a string is defined" do
-		before(:all) do
-			@my_string = "Renée is a fun teacher. Ruby is a really cool programming language"
-		end
-
-		it "should be able to count the charaters"
-
-		it "should be able to split on the . charater" do
-			pending
-			result = #do something with @my_string here
-			result.should have(2).items
-		end
-
-		it "should be able to give the encoding of the string" do
-			pending 'helpful hint: should eq (Encoding.find("UTF-8"))'
-			encodeing #do something with @my_string here
-			#use helpful hint here
-		end
-	end
+  context "When a string is defined" do
+    before(:all) do
+      @my_string = "Renee is a fun teacher. Ruby is a really cool programming language"
+    end
+
+    it "should be able to count the characters" do
+      "Renee is a fun teacher. Ruby is a really cool programming language".should have(66).characters
+      @my_string.size.should eq 66
+    end
+
+    it "should be able to split on the . character" do
+      #pending
+      result = @my_string.split(/\s*\.\s*/)
+      #do something with @my_string here
+      result.should have(2).items
+    end
+
+    it "should be able to give the encoding of the string" do
+
+      # I have ruby 1.9 so the encoding on my machine is US-ASCII
+      encoding = @my_string.encoding
+      #do something with @my_string here. 
+
+      encoding.should eq Encoding.find("UTF-8")
+    end
+  end
 end
 

week2/homework/questions.txt

@@ -4,10 +4,55 @@ Sharing Functionality: Inheritance, Modules, and Mixins
 
 1. What is the difference between a Hash and an Array?
 
+An Array is a list of object references. They are indexed by
+integers. A Hash is also a list of object references but there are 2
+objects and they are in pairs (keys and their values). A hash is
+indexed with any type of object (symbols, strings, regular expressions)
+
 2. When would you use an Array over a Hash and vice versa?
 
+An Array is used when you have a list of items and need to iterate
+over the list and return the items in it.  I'd also use an Array when
+I know I need to return the first n items.
+
+A Hash can create a more complex data structure. You can create a hash
+of hashes or arrays which can hold more associated data than an Array
+since an array can only be indexed by an integer. If I have lots of
+different references to store (a book, it's author, her birthday)I'd
+use a Hash.
+
+
 3. What is a module? Enumerable is a built in Ruby module, what is it?
 
+Modules are a way of grouping together methods, classes and
+constants. They provide a namespace and prevent name(p. 73)
+clashes. They support the mixin facility.
+
+(note to me: A module can't have instances because it's not a class.
+You can include a module within a class definition. Then all the
+module's instance methods are available as methods in the class as
+well. A mixed-in module behaves like a superclass.)
+
+Enumerable implements methods in terms of the host class's each
+method. Any class that includes the Enumerable object and uses the
+method each can use Enumerable's methods. Some of Enumerable's methods
+are map, sort_by, select, next, with_index. These are all methods that
+allow me create data structures, change them and keep track of
+them. I need to use each to use them.
+
+
 4. Can you inherit more than one thing in Ruby? How could you get around this problem?
 
+No. You can use a module so your names are protected.
+
+
 5. What is the difference between a Module and a Class?
+A module can't have instances. It has to be included in a file so it's
+methods can be used by the Class. Modules group classes together. A
+Classes are the things I deal with (ie. in my software I have a User class
+that holds all of my users, an Appointment class that holds all the
+appointments). Using modules I can bring that data together to change
+it or track it or whatever I am doing with it.
+
+I know I've used modules and I think I basically understand what they
+are. Classes seem more clear to me though.

week2/homework/simon_says.rb

@@ -0,0 +1,22 @@
+module SimonSays
+  def echo(word)
+    word
+  end
+
+  def shout(word)
+    word.upcase
+  end
+
+  def repeat(word, number=2)
+    space = "#{word} " * number
+    space.chop
+  end
+
+  def start_of_word(word, number)
+    word.slice(0,number)
+  end
+
+  def first_word(phrase)
+    phrase.split.first
+  end
+end

week3/homework/calculator.rb

@@ -0,0 +1,31 @@
+class Calculator
+
+ def sum(numbers=[])
+     @calculator = numbers.inject(0, :+)
+ end
+
+ def multiply(a, b=1)
+   if a.is_a?(Array)
+     @calculator = a[0]*a[1]
+   else
+     @calculator = a*b
+   end
+ end
+
+ def pow(a,b)
+   puts "a: #{a} b: #{b}"
+   @calculator = b.times do (a*a)
+     puts "ia: #{a} ib: #{b}"
+     end
+ end
+
+ def fac(number)
+   if (number == 0)
+     number +=1
+   end
+   @calculator = (1..number).inject(&:*)
+
+ end
+
+end
+

week3/homework/questions.txt

@@ -5,11 +5,36 @@ Please Read:
  - Chapter 22 The Ruby Language: basic types (symbols), variables and constants
 
 1. What is a symbol?
+A Ruby symbol is an identifier -- a name that corresponds to a string
+of characters. The characters can refer to different things --> a
+string, an object, a variable.
 
 2. What is the difference between a symbol and a string?
+A string is a type of symbol. It is one of many things a symbol can
+correspond to -- a symbol can also represent an object or a
+variable.  A Ruby symbol begins with a colon or %s notation.
+
+Question: I think %s notation is the use of % then {} to interpret
+string literals. Is that correct?
 
 3. What is a block and how do I call a block?
 
+A block is a set of Ruby statements and expressions between braces or
+a do/end pair. A block is not an object. It is a chunk of code
+attached to a method (p336). You can call a block by using braces {}
+or do/end after the arguments to a method or by using yield within the
+method.
+
+
 4. How do I pass a block to a method? What is the method signature?
 
+Attach a block to a method by passing the block after the method's
+arguments or by using yield. The signature is the braces or the do/end
+surrounding the block. 
+
 5. Where would you use regular expressions?
+Regular expressions are used on strings. A regexp can
+1. test a string to see whether it matches a pattern
+2. Extract from a string the sections that match all or part of the
+   pattern
+3. You can change the string, replacing parts that match a pattern (p 93)   

week4/homework/questions.txt

@@ -3,11 +3,35 @@ Chapter 10 Basic Input and Output
 The Rake Gem: http://rake.rubyforge.org/
 
 1. How does Ruby read files?
+Using gets method on the I/O object
+
 
 2. How would you output "Hello World!" to a file called my_output.txt?
 
+File.open(my_output.txt, "w") do |file|
+    file.puts "Hello World!"
+end
+puts File.read("my_output.txt")
+
 3. What is the Directory class and what is it used for?
+The Directory class represents directories in the underlying file
+system. Methods on this class allow move around the directory
+structure and manage it.
 
 4. What is an IO object?
+The base class to handle input and output. The base class is
+subclassed by classes File and BasicSocket to provide more specialized
+behavior. p153
 
 5. What is rake and what is it used for? What is a rake task?
+Rake is a build utility that uses Ruby code. It organizes and automates tasks. It takes
+a tasks and breaks it down into component pieces and then specifies what
+needs to be done in order to do the bigger task. All tasks have
+dependencies and they need to be in the right order to execute
+correctly. (I got that info from a lecture I found online by Jim
+Weirich.)
+A rake task is code that perform automated tasks. On my
+website, I use rake to send appointment reminders to nannnies and
+parents. I use a cron to activate the rake task. I have a rake task to
+change passwords on my development server. I only run that every now
+and then.

week4/homework/worker.rb

@@ -0,0 +1,13 @@
+class Worker
+
+  def self.work( num = 1 )
+    if num == 1
+      yield
+    else
+      num.times.inject(5, :+)
+    end
+
+  end
+
+
+end