swift3.0之正则表达式

如果通过Alamofire抓取到了一个html页面, 想从页面里,找到某组数字的最大值,可以通过正则表达式,找到所有数字,然后对比.

var baseurl = "http://www.xxx.com/book/"
var html = "1"

Alamofire.request(baseurl).responseJSON { response in
         if   let data = response.data,  let utf8Text = String(data: data, encoding: .utf8) {
                print("Data: \(utf8Text)") // original server data as UTF8 string

  //下面的匹配表达式里,book后面的6位数字,就是我想找的数字
  do {
       
         let r = "target=\"_blank\" href=\"http://www.xxx.com/book[0-9]{6}"

         let regex = try NSRegularExpression(pattern: r, options: NSRegularExpression.Options.caseInsensitive)
         //utf8Text即是html页面的data                           
         let res  = regex.matches(in: utf8Text, options: NSRegularExpression.MatchingOptions(rawValue:0), range: NSMakeRange(0, utf8Text.characters.count))

          //(utf8Text as NSString).substring(with: checkingRes.range) 是通过匹配模式匹配到的所有字符串. 通过字符串截取,取得最后的6位数字   
          for checkingRes in res {               
                print(((utf8Text as NSString).substring(with: checkingRes.range) as NSString).substring(from: 47))
          }

      }catch {
          print(error)
      }
                
   }
 }