题解 | #千分位#
分隔符
http://www.nowcoder.com/practice/e5696992841841a8ab9d026324e4bb77
function _comma(number) {
// 补全代码
let arr = Math.abs(number).toString().split('').reverse();
let i = 3;
while (i < arr.length) {
arr.splice(i, 0, ',');
i += 4;
}
let str = arr.reverse().join('');
return number >= 0 ? str : '-' + str;
}