One of these things is not like the other.

if_while_assignment.md

"if" statement assignment:

x = 0
y = if x == 0
  puts "test"
  'pizza'
end

# test
# => "pizza"
#> y
# => "pizza"

"while" statement assignment:

x = 0

y = while x < 2
  puts "test"
  'pizza'
  x += 1
end

# test
# test
#> => nil

#> y
#> => nil