تعبيرات case/when

التفرع متعدد المسارات

day = "Mon"
case day
when "Sat", "Sun"
  puts "Weekend"
else
  puts "Weekday"
end

أساسيات case / when

grade = "B"
case grade
when "A"
  puts "Excellent"
when "B"
  puts "Good"
when "C"
  puts "Okay"
end

قيم متعددة لكل when

char = "e"
case char
when "a", "e", "i", "o", "u"
  puts "Vowel"
else
  puts "Consonant"
end

فرع else

code = 500
case code
when 200
  puts "OK"
when 404
  puts "Not Found"
else
  puts "Other status"
end

case تعبير

score = 82
letter = case
when score >= 90 then "A"
when score >= 80 then "B"
else "C"
end
puts letter

الكلمة المفتاحية then

n = 3
case n
when 1 then puts "one"
when 2 then puts "two"
when 3 then puts "three"
end

مطابقة النطاقات

score = 73
case score
when 90..100 then puts "A"
when 70..89 then puts "B"
when 0..69 then puts "C"
end

المطابقة حسب الفئة

value = 3.14
case value
when Integer then puts "an integer"
when Float then puts "a float"
when String then puts "a string"
end

سحر ===

email = "jane@example.com"
case email
when /@/ then puts "Looks like an email"
else puts "No @ sign"
end

case من دون قيمة موضوع

temp = 5
case
when temp < 0 then puts "Freezing"
when temp < 15 then puts "Cold"
when temp < 25 then puts "Mild"
else puts "Warm"
end

تجميع المفاهيم

role = :admin
msg = case role
when :admin then "Full access"
when :editor then "Can edit"
when :viewer then "Read only"
else "No access"
end
puts msg

تحقق سريع

مراجعة

n = 42
kind = case
when n.zero? then "zero"
when n.positive? then "positive"
else "negative"
end
puts kind