将字符串拆分为块（不同大小）而不会破坏单词
我正在尝试创建一个方法，给定一个字符串，返回三个字符串：title，description1，description2
这是我发现的一个相关问题：将一个字符串拆分成指定大小的块而不会破坏单词 – 但我的块大小不同。
标题最多需要25个字符。
Description1需要最多35个字符。
Description2最多需要35个字符。
问题是：
如何拆分字符串以便最多创建三个实体（ 注意 ：如果字符串只能容纳第一个实体，那么我不需要返回三个实体），其中第一个实体具有最大值25个字符，另外两个最多35个字符。 使该方法足够聪明，可以考虑单词（也可能是标点符号），这样它就不会返回剪切结果。
我做了以下事情：
def split_text_to_entities(big_string) title = big_string(0..24) description1 = big_string(25..59) description2 = big_string(60..94) end 但这种方法的问题在于，如果输入是“从我们的商店购买我们的新品牌鞋。城里最优惠的折扣和首次购买的40％折扣。”，结果将是：
title = "Buy our new brand shoes f" description1 = "rom our store. Best discounts in to" description2 = "wn and 40% off for first purchase."
理想情况下他们会：
title = "Buy our new brand shoes" description1 = "from our store. Best discounts in" description2 = "town and 40% off for first"
所以，考虑到单词，尝试按字符大小分割。
这不是诀窍吗？：
def get_chunks(str, n = 3) str.scan(/^.{1,25}\b|.{1,35}\b/).first(n).map(&:strip) end
为了涵盖所有基础，我会做以下事情。
码
def divide_text(str, max_chars) max_chars.map do |n| str.lstrip! s = str[/^.{,#{n}}(?=\b)/] || '' str = str[s.size..-1] s end end
(?=\b)是一个（零宽度）正向前瞻，它与一个单词中断相匹配，即一个空格字符或字符串的结尾。
例子
max_nbr_chars = [25,35,35] str = "Buy our new brand shoes from our store. Best discounts in " + "town and 40% off for first purchase." divide_text(str, max_nbr_chars) #=> ["Buy our new brand shoes", # "from our store. Best discounts in", # "town and 40% off for first"] str = "Buy our new brand shoes from our store." divide_text(str, max_nbr_chars) #=> ["Buy our new brand shoes", "from our store.", ""] str = "Buy our new" divide_text(str, max_nbr_chars) #=> ["Buy our new", "", ""] str = "" divide_text(str, max_nbr_chars) #=> ["", "", ""] str = "Buyournewbrandshoesfromourstore." divide_text(str, max_nbr_chars) #=> ["", "Buyournewbrandshoesfromourstore.", ""] str = "Buyournewbrandshoesfromourstoreandshoesfromourstore." divide_text(str, max_nbr_chars) #=> ["", "", ""]
请注意，如果从正则表达式中省略了^ ：
str = "Buyournewbrandshoesfromourstore." divide_text(str, max_nbr_chars) #=> ["ewbrandshoesfromourstore.", "rstore.", ""]
s = "Buy our new brand shoes from our store. Best discounts in town and 40% off for first purchase." s =~ /\b(.{,25})\W+(.{,35})\W+(.{,35})\b/ [$1, $2, $3] # => # [ # "Buy our new brand shoes", # "from our store. Best discounts in", # "town and 40% off for first purchase" # ]