//------------------------------------------------ var a = function (nums) { nums.sort((a, b => a - b));//先进行排序,第一个跟第二个比,一旦有重复则返回false for (i = 0; i <= nums.length; i++) { if (nums[i] === nums[i + 1]) { return false; } } return true; } console.log(a([1, 2, 3]));//true console.log(a([1, 2, 3, 1]));//false