1、编写函数，求出100以内质数的和

		var a = 0;
        for(var i = 0; i<=100; i++){
             var b = 0;
             for(var j = 0; j<=i; j++){
                 if(i%j ===0){
                     b++;
                 }
             }
             if(b === 2){
                 a += i;
             }
         }
         console.log(a);

2、判断字符串中出现次数最多的元素并统计次数

var str = 'sdasdqweqwrqaszxasdsssss';
        var obj = {};
        var num = str.length;
        for( var  i=0; i<num; i++){
            if(obj[str.charAt(i)]){
                obj[str.charAt(i)] = parseInt(obj[str.charAt(i)])+1;

            }else{
                obj[str.charAt(i)] = 1;
            }
        }

        var max = 0;
        var maxDocument = null;
        for( var j in obj){
            if(obj[j]>max){
                max = obj[j];
                maxDocument = j;
            }
        }
        
        console.log('obj' ,obj);
        console.log('次数',max,"字符",maxDocument);

3、数组去重

 var arr = [1,1,2,3,4,3,4,3];
        var set = new Set(arr);

        console.log(Array.from(set));

4、使用冒泡或者选择排序

 var arr = [1,3,4,99,5,65,6];                                                                                        
        for(var j = 0; j<=(arr.length-1)-1; j++ ){

            for(var i = 0; i<=(arr.length-1)-1; i++){
                if(arr[i] > arr[i+1]){
                    var num = 0;
                    num = arr[i];
                    arr[i] = arr[i+1];
                    arr[i+1] = num;
                }
            }
        }
        console.log(arr);

5、实现一个ul,共有5个li，点某一个，输出当前的index

   var l = document.querySelectorAll("li");
        for(var i = 0; i<l.length; i++){
            l[i].index = i;
            l[i].onclick = function(){
                alert(this.index)
            }
        }

6、编写一个函数，可接受不定数量的参数实现对参数的排序并输出？

 var arr = new Array(1,3,49,0,2,3,2321);
        function max(a,b){
            return a-b;
        }

        arr.sort(max);
        console.log(arr);
        function fn() {
            var arr = []
            for (var i = 0; i < arguments.length; i++) {
                arr.push(arguments[i])
            }
            for (var i = 0; i < arr.length; i++) {
                for (var j = 0; j < arr.length; j++) {
                    if (arr[j] < arr[j + 1]) {
                        var t = 0;
                        t = arr[j]
                        arr[j] = arr[j + 1]
                        arr[j + 1] = t
                    }
                }
            }
            return arr
        }
        console.log(fn(5, 4, 2, 1, 5, 1, 5, 2));


            function deepClone(obj = {}){
                if(typeof obj !=='object' || obj == null){
                    return obj
                }

                let rusult;
                if(obj instanceof Array){
                    rusult = []
                }else {
                    rusult = {}
                }

                for(let key in obj){
                    if(obj.hasOwnProperty(key)){
                        rusult[key] = deepClone(obj[key])
                    }
                }
                return rusult
            }