java学习笔记---正则表达式

 test   - 判断字符串是否符合规定的正则
     rep = /\d+/;
     rep.test("asdfoiklfasdf89asdfasdf")# true

     rep = /^\d+$/;
     rep.test("asdfoiklfasdf89asdfasdf")# true

 exec   - 获取匹配的数据
     rep = /\d+/;
     str = "wangshen_67_houyafa_20"
     rep.exec(str)# ["67"]var pattern = /\bJava(\w*)\b/;
     # ["JavaScript", "Script"]JavaScript is more fun than Java or JavaBeans!var pattern = /\bJava\w*\b/g;
     # ["JavaScript"]# ["Java"]# ["JavaBeans"]# null

     全局匹配
     s = "JavaScript is more fun than Java or JavaBeans!"
     var pattern = /\bJava(\w*)\b/g;
     pattern.exec(s)    // /\bJava(\w*)\b/g.exec(s) 还是只能匹配第一个
     # ["JavaScript",'Script']pattern.exec(s)# ["Java", ""]pattern.exec(s)# ["JavaBeans", "Beans"]pattern.exec(s)# null

     /.../i   ：表示不区分大小写进行匹配

 多行匹配：
     默认就是多行匹配，唯一的区别是
     s = "JavaScript is more fun than \nJava or JavaBeans!"
     var pattern = /^Java(\w*)/g
     pattern.exec(s)# ["JavaScript", "Script"]pattern.exec(s)# null
     但是,用m进行多行匹配后
     var pattern = /^Java(\w*)/gm;
     pattern.exec(s)# ["JavaScript", "Script"]pattern.exec(s) #["Java", ""]