正则表达式使用实例

• 查找数字
  原生

找出字符串中的数字
(function(){
    function num(str) {
        let arr = [];
        let temp = '';
        for(let i = 0; i < str.length; i++) {
            if(str.charAt(i) <= '9' && str.charAt(i) >= '0') {
                //arr.push(str.charAt(i))
                temp += str.charAt(i);
            }
            else {
                if(temp){
                    arr.push(temp);
                    temp = '';     } } }
        if(temp){
            arr.push(temp);

        }
         console.log(arr)
    }
    let str = '123asf434sf43621wq345';
    num(str);
})();

正则表达式 /\d+/g

    let str1 = '123asf434sf43621wq345';
    let re = /\d+/g;
    console.log(str.match(re))

• 敏感词过滤

(function () {
    let str = '嘿嘿中国呵呵呵少年sp';
    let re = /嘿嘿|呵呵呵|sp/g;
    let result = str.replace(re,function (str0,str1,str2,str3) {
        let temp = '';
        if(str){
            for(let i = 0; i < str.length; i++){
                temp+='*'
            } }
        // console.log(temp)
        return temp;
    });
    console.log(result); //**中国***少年**
})();

• 找出重复次数最多的字符以及次数

(function(){
    // let str = 'asdaaassseedddddaffgyDXCvSSS';
    let str = 'aSdv';
    let re = /(\w)\1*/ig;
    //将字符串进行排序，把相同的字符放在一起
    let arr = str.toLowerCase().split('');
    // console.log(arr)
    str = arr.sort().join('');
    // console.log(str)
    let MaxLen = 0;
    let MaxValue = '';

    str.replace(re,function($0,$1,$2,$3,$4){
        console.log(arguments)
        if($0.length > MaxLen) {
            MaxLen = $0.length;
            MaxValue = $1;
        }else if($0.length === MaxLen){MaxValue += $1}
    })
    console.log(MaxValue+'.....'+MaxLen)
})();

• 去掉空格

(function(){
    let str = ' as  as d ';
    // let re = /^\s|\s/g; //去除全部空格
    let re = /^\s+|\s+$/g; //去除首尾空格
    console.log('('+str.replace(re,'')+')')
})()

trim用法