Intro to Ruby Challenges

Basic Challenges

Data Types

Store your first_name in a variable and your last_name in another variable.
```
 first_name = "Bob"
 last_name = "Smith"
```
Concatenate your first_name and last_name variables, and store the output in a new variable called full_name.
```
 full_name = "#{first_name} #{last_name}"
```
Use .split to turn your full_name variable into an array.
```
 full_name.split
```

Loops

Print (puts) "Ruby is awesome!" 50 times. Implement this 3 different ways, using:

while

 i = 0
 while i < 50
   puts "Ruby is awesome!"
   i += 1
 end

for

 for i in (1..50)
   puts "Ruby is awesome!"
 end

times

 50.times do
   puts "Ruby is awesome!"
 end

Save any string to a variable, then create an empty hash called count (count = {}). Loop through the string, and count occurrences of each letter. Store the counts in your hash like this example:

For the string apple, your count hash would look like this: {a: 1, p: 2, l: 1, e: 1}.
```
 str = "banana"
 count = {}
 i = 0
 while i < str.length
   if count[str[i]]
     count[str[i]] += 1
   else
     count[str[i]] = 1
   end
   i += 1
 end
```

Write a program that gets user input from the terminal and puts it until the input is the word "quit" or "q".

 input = nil
 while input != "quit" && input != "q"
   puts input if input
   puts "Enter input here:"
   input = gets.chomp
 end

Write a program that prints the "bottles of beer on the wall" song.

 verses = gets.chomp.to_i
 while verses > 0
   puts "#{verses} bottles of beer on the wall,"
   puts "#{verses} bottles of beer!"
   puts "Take one down and pass it around,"
   verses -= 1
   if verses == 1
     puts "#{verses} bottle of beer on the wall!"
   elsif verses == 0
     puts "No more bottles of beer on the wall."
   else
     puts "#{verses} bottles of beer on the wall!"
   end
   puts "----------"
 end

Iterators: Each

Define an array of 4 phrases: "Hello, world", "OMG", "Ruby", and "Pair Programming". Use .each to iterate over the array and puts each phrase.
```
 phrases = ["Hello, world", "OMG", "Ruby", "Pair Programming"]
 phrases.each do |phrase|
   puts phrase
 end
```
Iterate over your array of phrases again, but this time, only puts the phrase if its length 5 letters or longer. Otherwise, print a message that the phrase is too short, and include the phrase's index in the message (Hint: Look up .each_with_index).
```
 phrases.each_with_index do |phrase, index|
   if phrase.length >=5
     puts phrase
   else
     puts "Phrase at index #{index} is too short."
   end
 end
```

Iterators: Map

Write a program that maps an array of numbers to double each number.
```
 arr = [1, 2, 3]
 mapped_arr = arr.map {|num| num * 2}
```

Write a program that maps an array of words to the reverse of each word. (Hint: Look up .reverse)

 words = ["San Francisco", "General Assembly", "web development"]
 mapped_words = words.map {|word| word.reverse}

HTTParty

Install the httparty gem $ gem install httparty.

Now require it in a new ruby script file, and use it to call an album search on the word "White" to the spotify API.

 require 'httparty'
 response = HTTParty.get('https://api.spotify.com/v1/search?q=White&type=album')
 p response

Can you require both httparty and awesome_print to have the output look nice? (remember just require awesome_print and then use ap instead of p)

 require 'httparty'
 require 'awesome_print'

 response = HTTParty.get('https://api.spotify.com/v1/search?q=White&type=album')
 ap JSON.parse(response.body)

In the same file, can you write a loop that returns an array of the album names from your search?

require 'httparty'
require 'awesome_print'

response = HTTParty.get('https://api.spotify.com/v1/search?q=White&type=album')
body =  JSON.parse(response.body)
body["albums"]["items"].each do |a|
 ap a["name"]
end

Stretch Challenges

Create a simple temperature convertor.

 puts "Type '1' to convert from Celsius to Fahrenheit or '2' to convert from Fahrenheit to Celsius"
 response = gets.chomp
 if response == "1"
   puts "Enter Celsius temperature:"
   temp = (gets.chomp).to_i
   f_temp = (temp * 9/5) + 32
   puts "#{temp} degrees Celsius is equal to #{f_temp} degrees Fahrenheit"

 elsif response == "2"
   puts "Enter Fahrenheit temperature:"
   temp = (gets.chomp).to_i
   c_temp = (temp - 32) * (5/9)
   puts "#{temp} degrees Fahrenheit is equal to #{c_temp} degrees Celsius"
 end

Create a simple calculator that first asks the user what method they would like to use (addition, subtraction, multiplication, or division), then asks the user for two numbers, printing the result of the method with the two numbers.

 puts "What calculation would you like to do? (add, sub, mult, div)"
 response = gets.chomp

 puts "What is the first number?"
 num1 = (gets.chomp).to_f

 puts "What is the second number?"
 num2 = (gets.chomp).to_f

 if response == "add"
   result = num1 + num2

 elsif response == "sub"
   result = num1 - num2

 elsif response == "mult"
   result = num1 * num2

 elsif response == "div"
   result = num1 / num2
 end

 puts "The result is #{result}"

 # alternate solution (using case)
 puts "What calculation would you like to do? (add, sub, mult, div)"
 response = gets.chomp

 puts "What is the first number?"
 num1 = (gets.chomp).to_f

 puts "What is the second number?"
 num2 = (gets.chomp).to_f

 case response
   when "add" then result = num1 + num2
   when "sub" then result = num1 - num2
   when "mult" then result = num1 * num2
   when "div" then result = num1 / num2
 end

 puts "The result is #{result}"