This document discusses Ruby conditionals and control flow statements including if/else, unless, case, and truth values. It provides examples of using if/else statements with different conditions and modifiers. It also demonstrates using unless, case statements with ranges, regular expressions, and different data types, and truth values in Ruby.

1. CONDITIONALS
Sarah Allen

2. TRUTH
• Truth: Everything is true except for:
– false
– nil
• Therefore
– 0 is true
– “” is true

3. CONDITIONALS: IF
if age > 17
puts “can vote”
Statement Modifiers:
end do_something if x == 4
Other Syntax:
if x == 4 then do_something end
if age > 17
puts “can vote”
else
puts “attends school”
end

4. CONDITIONALS: IF
if age >= 21
puts “can drink”
elsif age > 17
puts “can vote”
else
puts “too young”
end

5. CHECKING FOR FALSE
if !(name == “superman”) …
if not (name == “superman”)
…

6. UNLESS
• “unless” provides us with another way of checking if a
condition is false:
unless human
status = "superhero"
end
status = "superhero" unless human

7. CASE
case superhero
when "superman"
city = "metropolis"
when "batman"
city = "gotham_city"
else
city = "central_city"
end

8. CASE REFACTORING
city = case superhero
when "superman"
"metropolis"
when "batman"
"gotham_city"
else
"central_city"
end

9. CASE
case num
when 1
puts "one"
when 2..5
puts "that is
small"
else
puts "pretty big"
end

10. CASE
case name
when "Sarah"
puts "awesome"
when /Mr.*/
puts "formal guy"
else
puts "whatever"
end

11. CASE
case args
when String
puts "Got a String"
when Array
puts "Got an Array”
when Hash
puts "Got a Hash"
end