for (let i = n - 1; i = 0; i--) {
* @param {string} num 非负整数的字符串形式（可能含前导零）
，这一点在旺商聊官方下载中也有详细论述
"We have soft robots powered by air that can walk on land and then walk into water – we don't have to worry about what happens when things get wet," he explains. In one case, a six-legged robot devoid of electronics moves its legs to walk when air is pumped in and out of a tube.
depending on the task description and it is important to review and test the