字串 String 一些好用的 function, scan, split, match, gsub, sub, grep

Scan
<br />=begin<br /> a = "cruel world"<br /> a.scan(/\w+/) #=> ["cruel", "world"]<br /> a.scan(/.../) #=> ["cru", "el ", "wor"]<br /> a.scan(/(...)/) #=> [["cru"], ["el "], ["wor"]]<br /> a.scan(/(..)(..)/) #=> [["cr", "ue"], ["l ", "wo"]]<br /><br /> $` before match string<br /> $' after match string<br /> $& entire match string<br />=end<br /><br /><br /><br />>> "111111222222333".scan(/....../).push($')<br />=> ["111111", "222222", "333"]<br />
<br /> def wbr_by_6(long_word)<br /> if long_word.chars.size > 6<br /> long_word.scan(/....../).push($').map{|m| CGI.escapeHTML(m)}.join('<wbr>')<br /> else<br /> CGI.escapeHTML(long_word)<br /> end <br /> end <br /> <br /> def format_content(content)<br /> <br /> def sub_url(text) <br /> if text =~ URI.regexp && $&[0,4] == 'http'<br /> "#{$`}<a href='#{$&}'>#{wbr_by_6($&)}</a>#{sub_url($')}"<br /> else<br /> #content = CGI.escapeHTML(content)<br /> wbr_by_6(text)<br /> end<br /> end<br /><br /> sub_url(content)<br /> end<br />
Split
<br />" now's the time".split #=> ["now's", "the", "time"]<br /> " now's the time".split(' ') #=> ["now's", "the", "time"]<br /> " now's the time".split(/ /) #=> ["", "now's", "", "the", "time"]<br /> "1, 2.34,56, 7".split(%r{,\s*}) #=> ["1", "2.34", "56", "7"]<br /> "hello".split(//) #=> ["h", "e", "l", "l", "o"]<br /> "hello".split(//, 3) #=> ["h", "e", "llo"]<br /> "hi mom".split(%r{\s*}) #=> ["h", "i", "m", "o", "m"]<br /><br /> "mellow yellow".split("ello") #=> ["m", "w y", "w"]<br /> "1,2,,3,4,,".split(',') #=> ["1", "2", "", "3", "4"]<br /> "1,2,,3,4,,".split(',', 4) #=> ["1", "2", "", "3,4,,"]<br /> "1,2,,3,4,,".split(',', -4) #=> ["1", "2", "", "3", "4", "", ""]<br /><br />>> %w[Tom Jerry and Mickey and Pluto].split('and')<br />=> [["Tom", "Jerry"], ["Mickey"], ["Pluto"]] <br />>> %w[Chris Mark Adam Tommy Martin Oliver].split { |name| name.first == 'M' }<br />=> [["Chris"], ["Adam", "Tommy"], ["Oliver"]]<br /><br />
Match and Scan 感受一下啥時要用啥吧
<br />MESSAGE_REGEX = /^([@#&?$\/>])\s*([^\s]+)\s*(\w*)/<br /><br />>> MESSAGE_REGEX.match("@lake lalaa ").to_a<br />=> ["@lake lalaa", "@", "lake", "lalaa"]<br />>> MESSAGE_REGEX.match("@lake lalaa 123").to_a<br />=> ["@lake lalaa", "@", "lake", "lalaa"]<br /><br />array 傳回的第一個是整個match 的部份, 後面是()的部份<br /><br />>> MESSAGE_REGEX.match("@lake lalaa 123").to_a.push($')<br />=> ["@lake lalaa", "@", "lake", "lalaa", " 123"]<br /><br />跟scan 很像吧, 玩玩有啥不同<br /><br />>> "@lake lalaa 123".scan(MESSAGE_REGEX)<br />=> [["@", "lake", "lalaa"]]<br />>> "@lake lalaa 123".scan(MESSAGE_REGEX).push($')<br />=> [["@", "lake", "lalaa"], " 123"]<br /><br />外面又包了一層 Array<br /><br />把regexp 的()拿掉<br />>> MESSAGE_REGEX = /^[@#&?$\/>]\s*[^\s]+\s*\w*/<br />(irb):57: warning: already initialized constant MESSAGE_REGEX<br />=> /^[@#&?$\/>]\s*[^\s]+\s*\w*/<br />>> "@lake lalaa 123".scan(MESSAGE_REGEX).push($')<br />=> ["@lake lalaa", " 123"]<br /><br />
gsub and sub 就是 replace 只是一個全部, 一個只有第一個
<br /> "hello".gsub(/[aeiou]/, '*') #=> "h*ll*"<br /> "hello".gsub(/([aeiou])/, '<\1>') #=> "h<e>ll<o>"<br /> "hello".gsub(/./) {|s| s[0].to_s + ' '} #=> "104 101 108 108 111 "<br />

<br />至少要是string, 3 連string 都不是<br />>> ["1","2",3].grep(/\d/)<br />=> ["1", "2"]<br />