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", ""]