字符串去重（以逗号隔开的字符串）

function stringDuplicateRemoval(str) { let obj = {}, arr = str.split(","), result = [], i = 0; for (let i = 0; i < arr.length; i++) { obj[arr[i]] = 1; } for (result[i++] in obj); return result; }; console.log(stringDuplicateRemoval('1,2,3,3')); // [1,2,3] console.log(stringDuplicateRemoval('1,2,3,3').toString()); // '1,2,3'