html - 显示一定长度的字符串而不截断

Question

我在 ruby​​ 中显示一定长度的字符串。一行中只能显示该字符串的 80 个字符。例如，如果字符串长度为 82，那么它将以 2 行显示，如果长度为 250，则字符串将以 5 行等显示，我想在空格而不是单词上拆分。

我是新手，不知道怎么解决。

Answer 1

def wrap(str, max_line_len)
  str.scan /(?<=\A| ).{1,#{max_line_len}}(?= |\z)/
end

str = "Little Miss Muffet she sat on her tuffet, eating her curds and whey. Along " + 
      "came a spider who sat down beside her and frightened Miss Muffet away."

         1         2         3    
123456789012345678901234567890123

puts wrap(str, 31)
Little Miss Muffet she sat on
her tuffet, eating her curds
and whey. Along came a spider
who sat down beside her and
frightened Miss Muffet away.

puts wrap(str, 32)
Little Miss Muffet she sat on
her tuffet, eating her curds and
whey. Along came a spider who
sat down beside her and
frightened Miss Muffet away.

puts wrap(str, 33)
Little Miss Muffet she sat on her
tuffet, eating her curds and
whey. Along came a spider who sat
down beside her and frightened
Miss Muffet away.

参见 String#scan 。正则表达式为“1 和 max_line_len 字符之间的匹配，紧接在字符串的开头或空格之前，紧接着是空格或字符串的结尾”。 (?<=\A| ) 是一个正向后视，而 (?= |\z) 是一个正向前视。