Question

所有

Ruby的新手并且在玩耍。这是我的数组：

fruits = ["banana", "apple", "pear", "orange"]

我这样积累了：

longest_sentence = fruits.inject("banana") do |memo, fruit|
  if memo == fruits[0]
    puts "I like " + fruit + "s and "
  else
    puts fruit + "s and "
  end
end

正如所料，它给了我这个：

I like bananas and 
apples and 
pears and 
oranges and 
=> nil

以下是我的两个问题：

您如何将此代码压缩为一行（即无代码块）？
您如何将结果显示为单个字符串（即“我喜欢香蕉，苹果，梨和橙子以及没有尴尬的线条返回”）？

谢谢！

Answer 1

您传递给reduce的参数应该是您希望memo拥有的初始值。在这种情况下，看起来您希望它是"I like"。此外，请勿在块内执行puts。 reduce（如map等）用于“构建”对象。完成后，打印您构建的字符串：

sentence = fruits.inject("I like") do |memo, fruit|
  memo << " #{fruit}s and"
end

puts sentence
# => I like bananas and apples and pears and oranges and

Answer 2

你不需要注入/减少。

fruits = ["banana", "apple", "pear", "orange"]
puts "I like " + fruits.map{|f| f + 's'}.join(' and ') 
# >> I like bananas and apples and pears and oranges

Answer 3

puts "I like #{fruits.join('s and ')}s" 
  #-> I like bananas and apples and pears and oranges

或

puts "I like %ss" % fruits.join("s and ")

Ruby＆gt; <注入方法>累积数组中的字符串

3 个答案: