Ruby on Rails Switch

Question

有人可以提供一个关于如何在Ruby中为变量使用switch case的例子吗？

Answer 1

我假设你指的是case/when。

case a_variable # a_variable is the variable we want to compare 
when 1 #compare to 1 
    puts "it was 1" 
when 2 #compare to 2 
    puts "it was 2" 
else 
    puts "it was something else" 
end 

或

puts case a_variable 
when 1 
    "it was 1" 
when 2 
    "it was 2" 
else 
    "it was something else" 
end 

编辑

东西也许不是每个人都知道，但什么是非常有用的是，你可以在一个case语句使用正则表达式。

foo = "1Aheppsdf" 

what = case foo 
when /^[0-9]/ 
    "Begins with a number" 
when /^[a-zA-Z]/ 
    "Begins with a letter" 
else 
    "Begins with something else" 
end 
puts "String: #{what}"