压缩几个条件语句比较相同的值

Question

我想知道是否有办法压缩这行代码:

elsif i == '+' || i == '-' || i == '/' || i == '*'

Answer 1

甲case when控制结构允许这样的稠线:

case i
when '+', '-', '/', '*'  # <= condensed line of code
  puts "operator!"
end