如何检查ruby中的属性的类类型?

How do I create a method like:

如何创建这样的方法:

def process_by_type *things

  things.each {|thing|
    case thing.type
      when String

      when Array

      when Hash

      end

    end
  }
end

I know I can use kind_of?(Array), etc. But I think this would be cleaner, and I cant' find a method for it on the Class:Object documentation page.

我知道我可以使用kind_of?(数组)，等等。但是我认为这样会更简洁，而且我在Class:Object documentation页面上找不到它的方法。

2 个解决方案

#1

Using the form of case statement like what you're doing:

使用案例陈述的形式，比如你正在做的事情:

case obj
  when expr1
    # do something
  when expr2
    # do something else
end

is equivalent to performing a bunch of if expr === obj (triple-equals comparison). When expr is a class type, then the === comparison returns true if obj is a type of expr or a subclasses of expr.

等于执行一系列if expr === = obj (triple-equals comparison)。当expr是类类型时，如果obj是expr的类型或expr的子类，则===比较返回true。

So, the following should do what you expect:

因此，以下几点应该符合您的期望:

def process_by_type *things

  things.each {|thing|
    case thing
      when String
        puts "#{thing} is a string"
      when Array
        puts "#{thing} is an array"
      when Hash
        puts "#{thing} is a hash"
      else
        puts "#{thing} is something else"
    end
  }
end

#2

Try .class:

试试. class:

>> a = "12"
=> "12"
>> a.class
=> String
>> b = 42
=> 42
>> b.class
=> Fixnum

#1