按降序排序
重要性：4
let arr = [5, 2, 1, -10, 8];
// ... your code to sort it in decreasing order
alert( arr ); // 8, 5, 2, 1, -10let arr = [5, 2, 1, -10, 8];
arr.sort((a, b) => b - a);
alert( arr );