js-14 正则篇 #

var re = /a/g   // a为字符串   推荐使用
var re = new RegExp(a)  // a为变量
var re = new RegExp("a")   // a为字符串

var str = '?name=hny&age=18'
var o = {}
var res;
let reg = /(\w+)=(\w+)/g
while(res = reg.exec(str)){
  // o[res[1]] = res[2]
  o[RegExp.$1] = RegExp.$2
}
console.log(o)

while(/(\w+)=(\w+)/g.exec(str)){} // 报错；

'2018-02-11'.replace(/(\d{4})\-(\d{2})\-(\d{2})/g,'$1/$2/$3')  // '2018/02/11'
'18782832656'.replace(/(\d{3})(\d{4})(\d{4})/,'$1****$3')

let str = 'abbkejsbcccwqaa'
str.match(/(\w)\1*/g);  // ['a','bb','k'.....]

// 判断双花括号的内容
let reg = /\{\{(.*)\}\}/

var str = '13388889999';
var re = /(\d{3})(\d{4})(\d{4})/   利用函数；
str.replace(re,function($0,$1,$2,$3){
    return $1 + '****' + $3;
}

var str = "18210399098";
var reg = /\d{4}/ig;
reg.lastIndex = 3;    //从第三位开始匹配；
console.log(str.replace(reg.exec(str), "****"));

const time = '2017-09-11'
const reg = /(?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2})/u
time.replace(reg,'$<day>/$<month>/$<year>')
let result = reg.exec(time)
console.log(result.groups) // 输出试试

/(?<word>[a-z])\k<word>/

let reg = /(\d{4})\D(\d{2})\D(\d{2}).*(\d{2}):(\d{2}):(\d{2})/gi
console.log(new Date().toLocaleString().replace(reg,'$1-$2-$3 $4:$5:$6'))

var str = '2019-4-17';
var re = /(\d+)(-)/g; 
str.replace(re,function($0,$1,$2){     
    //$0匹配成功的字符，$1匹配第一个小括号（子项）的，$2匹配第二个小括号（子项）；
    $2  //为第二个小括号的匹配项，为-，可以修改这个项；
}

str.replace(reg,function(cc){console.log(cc)});

// 例子1
var str = "北京，新疆，湖南，黑龙江，乌鲁木齐";
var reg = /北京|黑龙江|乌鲁木齐/g
var aa = str.replace(reg,function(val){ //循环替换里面的关键字  相当于执行了3遍
    console.log(val);
    var stm = "";
    for(var i=0;i<val.length;i++){ //循环文字的长度，将reg替换掉；
        stm+="*";
    }
    return stm;
});
console.log(aa);  // **，黑龙江，新东方，****，西藏

// 例子2 转换驼峰命名法;
const toCameLize = str.replace(/-(\w)/g,(_,c)=>(c ? c.toUpperCase() : ''))
console.log(ab-cd-ef) // abCdEf;

var str = '2019-4-17 15:25:25';
var re = /-|\s|:/g;    // 以-或\s或：分隔

var str = "123hdsajkfd4355jkdslaf888"
str.match(/\d+/g);   //默认查找一次   g查找全部
输出之后：ary[‘123’,’4355‘,’888‘]   //输入全部数字；

var arr = ['book','slice','root','dlick'];
var arr1 = arr.filter(value=>value.match(/oo/g));

var str = "18210399098";
var reg = /\d{4}/ig;
reg.lastIndex = 3;    //从第三位开始匹配；
console.log(str.replace(reg.exec(str), "****"));

// 前瞻:
e(?=f) e后边是f就匹配  f不会放进结果里;   ?:则会放进结果里;
// 负前瞻:
e(?!f) e后边不是f就匹配   ?!f  将=换成!  则为取非;
// 后顾:
(?<=f)e e前面是f就匹配
// 负后顾:
(?<!f)e e前面不是f就匹配

let a = '123ab'
a.match(/\d+(?=ab)/) // 123   ab不会放进结果里
a.match(/\d+(?:ab)/)  // 123ab  ab会放进结果里
a.match(/\d+(?!bc)/)  //123   后面不能是bc，bc是不会放入到匹配结果内的;
a.match(/(?<=\d)[a-z]+/)   //ab   匹配紧跟着数字后的字母;

   //匹配字母之间的数字；
let a = 'qee132ab'; 
a.match(/(?<=[a-z]+)\d+(?=[a-z]+)/)  //  ?=匹配为ab的;
//["132", index: 3, input: "qee132ab", groups: undefined]

// 匹配的是后面3*n个数字的非单词边界(\B)
console.log('12345678'.replace(/\B(?=(?:\d{3})+(?!\d))/g, ','))   

/* 原理解析: 
 * 查找3n正整数和1个非数字, 8后面没有数字了, 因此需要加一个非数字
 * 其实不加?:也行,但大多数加上
 */

'abbbb'.replace(/ab+/,'-')   //则结果是'-';
'abbbb'.replace(/ab+?/,'-')   // 则结果是'-bbb';

// 大家好,我叫{{name}},今年{{age}}岁
/{{(.*)}}/   // 我叫{{直到}}岁;   贪婪模式匹配到结尾;
/{{(.*?)}}/   // 我叫{{}},今年{{}}岁;  添加?开启非贪婪模式;

var reg = {
        phone: /^1\d{10}$/
        qq : /^[1-9][0-9]{4,9}$/
        email : /^\w+@\w+\.(com|cn|com.cn|wang|cc|xin|ren|info|xyz|site|club|win|net|org)$/
        space : /^\s*|\s*$/g
        身份证：/^[1-9]\d{14}|[1-9]\d{17}|[1-9]\d{16}x$/
        匹配中文：/[\u4e00-\u9fa5]/g
        固话：/^0\d{2,3}-[1-9]\d{6,7}$/
        网址：/^[a-zA-Z]+:\/\/[^\s]+$/
        密码：/^(?=.*[a-zA-Z])(?=.*[1-9])(?=.*[\W]).{6,}$/;
        格式化金钱：/\B(?=(\d{3})+(?!\d))/g,
}

const str = "The apple tree originated in Central Asia. It is cultivated worldwide. Apple matures in late summer or autumn."

// 查找包含单词“ apple”的句子
str.match(/[^.!?]*\bapple\b[^.!?]*.?/gi)

// 输出结果
// => ["The apple tree originated in Central Asia.", "Apple matures in late summer or autumn."]

const str = "https://en.wikipedia.org/"

str.replace(/[<>|:"*?\\/]+/g, '')
// => "httpsen.wikipedia.org"

const str = "  My    opinions may  have changed,    but not the fact that I'm right."

str.replace(/\s\s+/g, ' ')
// => " My opinions may have changed, but not the fact that I'm right."

str.replace(/(\s)\1+/g, '$1').trim(); // 需要.trim 去除结尾跟开头的空格

const input1 = "John543";
const input2 = ":-)";
/^[A-Z0-9]+$/i.test(input1);    // → true
/^[A-Z0-9]+$/i.test(input2);    // → false

const str = "Visit https://en.wikipedia.org/ for more info.";
str.replace(/\b(https?|ftp|file):\/\/\S+[\/\w]/g, '<a href="$&">$&</a>')

// => "Visit <a href="https://en.wikipedia.org/">https://en.wikipedia.org/</a> for more info."

const str = "This this sentence has has double words."

str.replace(/\b(\w+)\s+\1\b/gi, '$1')

// => "This sentence has double words."

var trim = /^\s*|\s*$/g