TypeScript版冒泡

maopao(arr: number[], num: number): number[] {        let item = 0;        let temp;        for (var index = 1; index < arr.length - num; index++) {            var element = arr[index];            if (arr[index] < arr[index - 1]) {                temp = arr[index];                arr[index] = arr[index - 1];                arr[index - 1] = temp;                item++;            }        }        if (item == 0)            return arr;        else            return this.maopao(arr, ++num);    }