将输出格式化为每行 40 个字符长 [英] Format output to 40 characters long per line

问题描述

我对 Ruby 还很陌生，现在我已经在 Google 上搜索了几个小时.有谁知道如何将打印输出的格式设置为不超过 40 个字符?

I'm fairly new to Ruby and I've been searching Google for a few hours now. Does anyone know how to format the output of a print to be no more than 40 characters long?

例如:

我要打印的内容:

This is a simple sentence.
This simple
sentence appears
on four lines. 

但我希望它的格式为:

This is a simple sentence. This simple
sentence appears on four lines.

我将原始的每一行放入一个数组中.
所以 x = ["This is a simple sentence.", "This simple", "sentence appears", "on 三行."]
我试过 x.each { |n|print n[0..40], " " } 但它似乎没有做任何事情.

I have each line of the original put into an array.
so x = ["This is a simple sentence.", "This simple", "sentence appears", "on three lines."]
I tried x.each { |n| print n[0..40], " " } but it didn't seem to do anything.

任何帮助都会很棒！

推荐答案

方法 word_wrap 需要一个 Strind 并进行一种漂亮的打印.

The method word_wrap expects a Strind and makes a kind of pretty print.

您的数组通过 join(" ")

Your array is converted to a string with join(" ")

代码:

def word_wrap(text, line_width = 40 ) 
  return text if line_width <= 0
  text.gsub(/
/, ' ').gsub(/(.{1,#{line_width}})(s+|$)/, "\1
").strip
end

x = ["This is a simple sentence.", "This simple", "sentence appears", "on three lines."]

puts word_wrap(x.join("
"))
x << 'a' * 50 #To show what happens with long words
x << 'end'
puts word_wrap(x.join("
"))

代码说明:

x.join(" ")) 构建一个字符串，然后用 text.gsub(/ /, ' ') 构建一个长行.在这种特殊情况下，这两个步骤可以合并:x.join(" "))

x.join(" ")) build a string, then build one long line with text.gsub(/ /, ' '). In this special case this two steps could be merged: x.join(" "))

现在魔法发生在

gsub(/(.{1,#{line_width}})(s+|$)/, "\1
")

• (.{1,#{line_width}})):取任意字符，不超过 line_width 个字符.
• (s+|$):下一个字符必须是空格或行尾(换句话说:如果最后一个匹配，前一个匹配可能比 line_width字符没有空格.
• "\1 ":取最多 40 个字符长的字符串并以换行符结束.
• gsub 重复包装直到完成.
• (.{1,#{line_width}})): Take any character up to line_width characters.
• (s+|$): The next character must be a space or line end (in other words: the previous match may be shorter the line_width if the last character is no space.
• "\1 ": Take the up to 40 character long string and finish it with a newline.
• gsub repeat the wrapping until it is finished.

最后，我用 strip

我还添加了一个长词(50 a's).怎么了?gsub 不匹配，单词保持原样.

I added also a long word (50 a's). What happens? The gsub does not match, the word keeps as it is.

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