ruby是否有数组方法选择!或不？

Question

> a = %w(a b c)
 => ["a", "b", "c"] 
> a.select!{|e| !e.nil?}
NoMethodError: undefined method `select!' for ["a", "b", "c"]:Array
    from (irb):2

ruby 1.8.7 (2010-04-19 patchlevel 253) [i686-darwin10.5.0], MBARI 0x6770, Ruby Enterprise Edition 2010.02

该文档称有一种名为select的方法!在数组中.

http://www.ruby-doc.org/core/classes/Array.html#M000252

Answer 1

但是Ruby 1.8.7 确实有Array#reject!:

>> a = [1, 2, nil]
=> [1, 2, nil]
>> a.reject! &:nil?
=> [1, 2]

Answer 2

您链接的文档适用于Ruby 1.9.2.Ruby 1.8.7 Arrays没有select!.

编辑:作为未来的参考,您可以查看不同版本的Ruby的文档.