全面详解JS正则中匹配技巧及示例

//  将1999-12-31时间格式转化为/1999/12/31 
const RE_DATE = /(\d{4})-(\d{2})-(\d{2})/; 
const matchObj = RE_DATE.exec('1999-12-31');
const year = `${matchObj[1]}/${matchObj[2]}/${matchObj[3]}`; //1999/12/31 

//  1999-12-31 -> 1999/12/31
const RE_DATE = /(?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2})/;
const matchObj = RE_DATE.exec('1999-12-31');
const year = `${matchObj.groups.year}/${matchObj.groups.month}/${matchObj.groups.day}`;
console.log(year) // 1999/12/31

let {groups: {one, two}} = /^(?<one>.*):(?<two>.*)$/u.exec('foo:bar');
console.log(one,two)  // foo,bar

// 1999-01-02 -> 02/01/1999
let re = /(?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2})/u;
let str = '1999-01-02'.replace(re, '$<day>/$<month>/$<year>')
console.log(str) // 02/01/1999

// 前瞻：
A(?=B)   //查找B前面的A
// 后顾：
(?<=B)A   //查找B后面的A
// 负前瞻：
A(?!B)   //查找后面不是B的A
// 负后顾：
(?<!B)A   //查找前面不是B的A

const reg1 = /(http|https)\:\/\/+(.+\?)(?=(\w))/g
let str = 'https://open.weibanzhushou.com/open-api/chat/message/list?num=aa&key=123aa';
str = str.replace(reg1,'')
console.log(str); // num=aa&key=123aa

 const reg1 = /(\<|\<\/)\w{1,}\>/g; 
 // 等同于 /(\<|\<\/)\w*\>/g 
 // 等同于 /(\<|\<\/)\w+\>/g
    str = str.replace(reg1,'-'); 
    console.log(str.split('-')); //[' asdasd', 'aas', 'asd', 'asda', 'asad', 'asd ']

const reg1 = /\d{1,3}(?=(\d{3}))/;
let num = '10000';
num = num.replace(reg1,'$&,');//10,000 

const origin = 'abc1abc' 
const newStr = origin.replace(/\d/g, '<<$&>>');
// newStr = 'abc<<1>>abc

  const origin = '2022-07-08' 
    const newStr = origin.replace(/(\d{4})-(\d{2})-(\d{2})/g, '$1/$2/$3');
    console.log(newStr)