ruby - 为什么这个 .each block 返回的结果与 .select 不同？

Question

来自 CodeQuizzes #6:使用包含字母“a”的所有元素从 captain_planet 数组创建一个新数组。

captain_planet = ["earth", "fire", "wind", "water", "heart"]

我理解他们的回答:

captain_planet.select do |word|
  word.include?("a")
end

但是，我似乎无法弄清楚为什么这不会返回相同的东西:

ret = []

captain_planet.each do |x|
    if x.include?('a')
        ret.push(x)
    end
end

想法？

Answer 1

尝试在 block 结束后查看 ret 的输出。

2.0.0p247 :001 > ret = []
 => []
2.0.0p247 :002 > captain_planet = ["earth", "fire", "wind", "water", "heart"]
 => ["earth", "fire", "wind", "water", "heart"]
2.0.0p247 :003 > captain_planet.each do |x|
2.0.0p247 :004 >         if x.include?('a')
2.0.0p247 :005?>             ret.push(x)
2.0.0p247 :006?>         end
2.0.0p247 :007?>   end
 => ["earth", "fire", "wind", "water", "heart"]
2.0.0p247 :008 > puts ret
earth
water
heart
 => nil