RSPEC Practice Exercises

00_hello/hello.rb

@@ -0,0 +1,7 @@
+def hello
+  "Hello!"
+end
+
+def greet(who)
+  "Hello, #{who}!"
+end

01_temperature/temperature.rb

@@ -0,0 +1,9 @@
+#convert fahrenheit to celsius
+def ftoc(temp_f)
+  (temp_f - 32) * (5.0/9.0)
+end
+
+#convert celsius to fahrenheit
+def ctof(temp_c)
+  (temp_c) * (9.0/5.0) + 32
+end

02_calculator/calculator.rb

@@ -0,0 +1,32 @@
+def add(num_1, num_2)
+  num_1 + num_2
+end
+
+def subtract(num_1, num_2)
+  num_1 - num_2
+end
+
+def sum(array)
+  sum = 0
+  array.each {|num| sum += num}
+  sum
+end
+
+def multiply(*args)
+  product = 1
+  args.each {|num| product *= num}
+  product
+end
+
+def power(base, exponent)
+  result = 1
+  exponent.times {result*=base}
+  result
+end
+
+def factorial(num)
+  return 1 if num == 0 #by definition
+  result = 1
+  (1..num).each {|x| result *= x}
+  return result
+end

02_calculator/calculator_spec.rb

@@ -79,21 +79,37 @@
 
 describe "#multiply" do
 
-  it "multiplies two numbers"
+  it "multiplies two numbers" do
+    expect(multiply(10,4)).to eq(40)
+  end
+
+  it "multiplies several numbers" do
+    expect(multiply(2,3,4)).to eq(24)
+  end
 
-  it "multiplies several numbers"
-
 end
 
 describe "#power" do
-  it "raises one number to the power of another number"
+  it "raises one number to the power of another number" do
+    expect(power(3,2)).to eq(9)
+  end
 end
 
 # http://en.wikipedia.org/wiki/Factorial
 describe "#factorial" do
-  it "computes the factorial of 0"
-  it "computes the factorial of 1"
-  it "computes the factorial of 2"
-  it "computes the factorial of 5"
-  it "computes the factorial of 10"
+  it "computes the factorial of 0" do
+    expect(factorial(0)).to eq(1)
+  end
+  it "computes the factorial of 1" do
+    expect(factorial(1)).to eq(1)
+  end
+  it "computes the factorial of 2" do
+    expect(factorial(2)).to eq(2)
+  end
+  it "computes the factorial of 5" do
+    expect(factorial(5)).to eq(120)
+  end
+  it "computes the factorial of 10" do
+    expect(factorial(10)).to eq(3628800)
+  end
 end

03_simon_says/simon_says.rb

@@ -0,0 +1,38 @@
+def echo(str)
+  str
+end
+
+def shout(str)
+  str.upcase
+end
+
+def repeat(str, num=2)
+  result = (str + ' ') * num
+  result[0..-2] #remove trailing space
+end
+
+def start_of_word(str, num=1)
+  str[0..num-1]
+end
+
+def first_word(str)
+  str.split(' ')[0]
+end
+
+
+def titleize(str)
+  result = str.split(' ').each_with_index do |word, index|
+    if index == 0
+      word.capitalize!
+    elsif (word != 'and') && (word != 'over') && (word != 'the')
+      word.capitalize!
+    end
+
+  end
+  result.join(' ')
+end
+
+# # p first_word('hello there')
+# z = ''
+# z=  'david copperfield'.split(' ').each {|x| x.capitalize!}
+# p z.join(' ')

04_pig_latin/pig_latin.rb

@@ -0,0 +1,39 @@
+def translate (words)
+  result = words.split(' ').each do |word|
+
+    #check for 'qu'
+    if word.index('qu')
+      word.insert(-1, word[0..word.index('qu')+1])
+      word.slice!(0..word.index('qu')+1)
+      word << 'ay'
+      next
+
+      #check if first 3 letters are consonants
+    elsif word[0] =~ (/[^aeiou]/) && word[1] =~ (/[^aeiou]/) && word[2] =~ (/[^aeiou]/)
+      word.insert(-1, word[0..2])
+      word.slice!(0..2)
+      word << 'ay'
+      next
+
+      #check if first 2 letters are consonants or word starts with 'qu'
+    elsif word[0] =~ (/[^aeiou]/) && word[1] =~ (/[^aeiou]/)
+      word.insert(-1, word[0..1])
+      word.slice!(0..1)
+      word << 'ay'
+      next
+
+      #check if first letter is a consonant
+    elsif word[0] =~ (/[^aeiou]/)
+      word.insert(-1, word[0])
+      word.slice!(0)
+      word << 'ay'
+      next
+      #first letter will be a vowel
+    else
+      word << 'ay'
+    end
+  end
+  result.join(' ')
+end
+
+# p translate('apple pie')

05_silly_blocks/silly_blocks.rb

@@ -0,0 +1,16 @@
+def reverser
+
+  yield.split(' ').each {|word| word.to_s.reverse!}.join(' ')
+
+end
+
+def adder(num=1)
+  yield + num
+end
+
+
+def repeater(numtimes=1)
+
+    numtimes.times {yield}
+
+end

06_performance_monitor/performance_monitor.rb

@@ -0,0 +1,11 @@
+require "time"
+
+def measure(num_times=1)
+
+    start_time = Time.now
+    num_times.times {yield}
+    (Time.now-start_time)/num_times #average time
+
+end
+
+puts Time.now()

07_hello_friend/friend.rb

@@ -0,0 +1,9 @@
+class Friend
+  def greeting(who=nil)
+    if who
+      "Hello, #{who}!"
+    else
+      "Hello!"
+    end
+  end
+end

08_book_titles/book.rb

@@ -0,0 +1,19 @@
+class Book
+  attr_reader :title
+
+  def title=(title)
+    #words to not capitalize
+    wordslist = ["and", "over", "the", "a", "in", "of", "an"]
+
+    @title = title
+    result= @title.split(' ').each_with_index do |word, index|
+      if index == 0
+        word.capitalize!
+      elsif wordslist.index(word) == nil
+        word.capitalize!
+      end
+    end
+    @title = result.join(' ')
+  end
+
+end

09_timer/timer.rb

@@ -0,0 +1,20 @@
+class Timer
+  def initialize
+    @seconds = 0
+  end
+
+  attr_reader :seconds
+
+  def seconds=(seconds)
+      @seconds = seconds
+  end
+
+  def time_string
+    hours = @seconds / 3600
+    mins = (@seconds % 3600) / 60
+    secs = (@seconds % 3600) % 60
+    format("%02d:%02d:%02d", hours, mins, secs)
+
+  end
+
+end

10_temperature_object/temperature.rb

@@ -0,0 +1,45 @@
+class Temperature
+
+
+  def initialize(temp = {})
+    @temp = temp
+
+  end
+
+  def Temperature.from_celsius(temp_c)
+    Temperature.new(:c => temp_c)
+  end
+
+  def Temperature.from_fahrenheit(temp_f)
+    Temperature.new(:f => temp_f)
+  end
+
+  def in_fahrenheit
+    if @temp[:f]
+      @temp[:f]
+    elsif @temp[:c]
+      (@temp[:c]) * (9.0/5.0) + 32
+    end
+  end
+
+  def in_celsius
+    if @temp[:c]
+      @temp[:c]
+    elsif @temp[:f]
+      (@temp[:f] - 32) * (5.0/9.0)
+    end
+  end
+end
+
+class Celsius < Temperature
+  def initialize(temp)
+    super(:c => temp)
+  end
+end
+
+class Fahrenheit < Temperature
+  def initialize(temp)
+    super(:f => temp)
+  end
+
+end

11_dictionary/dictionary.rb

@@ -0,0 +1,49 @@
+class Dictionary
+
+  def initialize
+    @dic = {}
+  end
+
+  def entries
+    @dic
+  end
+
+  def add(entry)
+    if entry.is_a?(Hash)
+      @dic.merge!(entry)
+      #add key only
+    elsif entry.is_a?(String)
+      @dic.merge!({entry => nil})
+    end
+  end
+
+  def keywords
+    @dic.keys.sort!
+  end
+
+  def include?(key)
+    @dic.key?(key)
+  end
+
+  def find(string)
+    results = {}
+    @dic.each do |key,val|
+      if key.index(string)
+        #if the key contains the search string, add k-v pair to results
+        results.merge!({key => val})
+      end
+    end
+    results
+  end
+
+  def printable
+    hash = entries.sort
+    result = ""
+    hash.each do |key,val|
+    result << "[#{key}] \"#{val}\"\n"
+    end
+    result
+
+  end
+
+end