wyncode.rb

wyncode.rb

# My favorite questions from the Wyncode Ruby Units
# 
#UNIT: Ruby syntax.

puts "Ruby Syntax: Float Money"
puts <<FLOATMONEY
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| Question |
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Someone buys a product from your website for $33.50. 
You don’t trust float money because it can introduce fractional pennies. 
And you don’t want to use any rounding or truncating strategies.

In words, describe something you could do with a Float to help you keep track of this money value?

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|My Answer:|
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To avoid a possible rounding error, I would call the rationalize (.rationalize) method on my Float objects 
to convert them into rational objects, which are exact. 
The operations I perform on my new rational objects would not suffer from rounding problems.

After all operations are performed, I would convert the results back to Float with the .to_f method for viewing.
FLOATMONEY

#Unit:  RUBY DATA TYPES: PUSH IT GOOD

puts "Ruby Data Types: Push it Good"
puts <<PUSHIT
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| Question |
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What’s the difference between these two Ruby expressions?
[1,2,3].push(1,2,3)
[1,2,3].push([1,2,3])

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|My Answer:|
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[1,2,3].push(1,2,3) will append the values integers 1,2, and 3 to the existing array. Result: [1,2,3,1,2,3]
[1,2,3].push([1,2,3]) will append the array [1,2,3] to the existing array. Result: [1,2,3,[1,2,3]]

PUSHIT

#Unit:  RUBY DATA TYPES: SPLIT JOIN

puts "Ruby Data Types: Split Join"
puts <<SPLITJOIN
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| Question |
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Using a combination of Array’s join method and String’s split method, 
write a single Ruby expression that converts [1,2,3] into ["1", "2", "3"].

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|My Answer:|
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[1,2,3].join(“ ”).split

SPLITJOIN

#Unit:  RUBY DATA TYPES:  STRING VS. SYMBOL

puts "Ruby Data Types: Strings vs. Symbol"
puts <<STRING
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| Question |
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How many methods does the String "a" have that the Symbol :a doesn’t? 
Calculate the difference with Ruby.

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|My Answer:|
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(“a”.methods - :a.methods).count
=> 91

It is NOT the same result if the command is:
("a".methods.count)-(:a.methods.count)
=> 89

STRING

#Unit: RUBY DATA TYPES: SYMBOL VS. STRING

puts "Ruby Data Types: Symbols vs. Strings"
puts <<SYMBOL
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| Question |
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How many methods does the Symbol :a have that the String "a" doesn’t? 
Calculate the difference with Ruby.

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|My Answer:|
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:a.methods - “a”.methods
=> [:id2name, :to_proc]

Answer: 2

SYMBOL

#Unit: RUBY DATA TYPES: BE RATIONAL

puts "Ruby Data Types: Be Rational"
puts <<RATIONAL
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| Question |
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1 - 1.0/3 produces the wrong answer (0.6666666666666667) because it outputs a Float. 
But Ruby’s standard library contains something called a Rational that can express “⅓” correctly. 
Can you rewrite the Ruby expression so that it returns the correct result?

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|My Answer:|
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((1.rationalize) - (1.0.rationalize)/(3.rationalize))
=> (2/3)


Additional correct answers:

1 - 1.0.to_r/3  => (2/3)

Or

1 - "1.0/3".to_r => (2/3)

Or

1 - Rational("1/3") => (2/3)
1 - Rational(1,3) => (2/3)

1 - 1.rationalize/3 => (2/3)

RATIONAL

#Unit:  RUBY DATA TYPES: STRINGY CHRISTMAS TREE

puts "Ruby Data Types: Stringy Christmas Tree"
puts <<CHRISTMAS
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| Question |
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print a single String containing newline characters that looks like a Christmas tree.
    x
   xxx
  xxxxx
 xxxxxxx
xxxxxxxxx
Make some of your own String art as well.

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|My Answer:|
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print “    x\n   xxx\n  xxxxx\n xxxxxxx\nxxxxxxxxx\n”
print “xxxxx\nxxxx\nxxx\nxx\nx\nx\nxx\nxxx\nxxxx\nxxxxx\n”

CHRISTMAS


#Below is the code actually running!

print "    x\n   xxx\n  xxxxx\n xxxxxxx\nxxxxxxxxx\n"
print "xxxxx\nxxxx\nxxx\nxx\nx\nx\nxx\nxxx\nxxxx\nxxxxx\n"