娃娃鸭学Ruby-28、Case

Case

name= case
          where x==1 then "one"
          where x==2 then "two"
          where x==3 then "three"
          where x==4 then "four"
          else "many"
          end
同if

case
    where x==1
         "one"
    where x==2
         "two"
    where x==3
         "three"
end

case
where x==1,y==0 then "x is one or y is zero"
where x==2||y==1 then "x is two or y is one "
end

name=case x
  when 1
      "one"
   when 2 then "two"
   when 3; "three"
   else "many"
end

name= case
   when 1===x then "one"
   when 2===x then "two"
   when 3===x then "three"
   else "many"
   end
===是条件相等性操作符

puts case x
       when String then "string"
       when Numeric then "number"
       when TrueClass,FalseClass then "boolean"
       else "other"
end

tax=case income
  when 0..7550
      income *0.1
  when 7500..30650
     755+(income-7550)*0.15
  when 30650..742000
     4220 +(income-30655)*0.25
  when 74200..154800
    15107.5+(income-74201)*0.28
  when 154800..336550
   37675.5+(income-154800)*0.33
  else
97653 +(income-336550)*0.35
end

when line=gets.chomp do
       case line
         when /^\s*#/
              next
          when /^quit$/i
               break
           else
               puts line.reverse
          end
end

def hasValue?(x)
case x
    when nil,[],"",0   # if nil===x || []===x || ""===x || 0===x then
             false
       else
           true
     end
end

2011-4-19 13:28 danny