ruby - ruby有数组方法select吗!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

文档说有一个叫做select的方法!在数组中。

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

Answer 1

Ruby 1.8.7 确实有 Array#reject!，但是:

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