sell -- js， 字符串去重，找到字符串中出现最多次数的字符，且输出多少次

1.

    var str = "123456654123789999999879999"
    findMostAppearNum(str);

    function findMostAppearNum(str) {
        str = str.split('').sort().join('')
        var re = /(w)1+/g;
        var value = '';
        var count = 0;
        str.replace(re, function ($0, $1) {
            if (count < $0.length){
                count = $0.length; //$0 每个重复项
                value = $1; //重复项的具体值
            }
        });
        alert('出现次数最多的字符是：'+ value+"共出现了："+count+"次")
    }


    var str1 = "a a b a b e";
    var str2 = "123456654123789999999879999"
    console.log(removeDup(str1));
    console.log(removeDup(str2));

    function removeDup(str) {
        var arr =  str.trim().split("").sort();
        var len = arr.length - 1;
        for (var i = len; i > 0; i--) {
            if (arr[i] == arr[i - 1]) {
                arr.splice(i, 1); // 后面和前面的一样删除后面的，如此反复
            }
        }
        return arr
    }

 2.

    var arr = [1,1,2,2,3,44,5,5,5];
    for(var i = 0; i < arr.length; i++) {
        for(var j = i+1; j <arr.length; j++){
            if (arr[i] == arr[j]){
                arr.splice(j, 1);
                j--; //删除了以为，数组下标要改变
            }
        }
    }
    alert(arr)