数组去重

1 var arr = [{id:1},{id:3},{id:1},{id:4}];
2 var newArr = arr.filter((value, index, array) => {
3 console.log(value,index,array.map((item) => {return item.id;}).indexOf(value.id));
4 return array.map((item) => {return item.id;}).indexOf(value.id) == index
5 });
6 console.log(newArr)

输出：

1 var arr = [1, 2, 2, 3, 3, 3, 4, 5];
2 var newArr = arr.filter((value, index, array) => array.indexOf(value) === index);
3 console.log(newArr)

输出：

 1 /*
 2     * JSON数组去重
 3     * @param: [array] json Array
 4     * @param: [string] 唯一的key名，根据此键名进行去重
 5     */
 6 export function uniqueArray(array, key) {
 7   var result = [array[0]];
 8   for (var i = 1; i < array.length; i++) {
 9     var item = array[i];
10     var repeat = false;
11     for (var j = 0; j < result.length; j++) {
12       if (item[key] == result[j][key]) {
13         repeat = true;
14         break;
15       }
16     }
17     if (!repeat) {
18       result.push(item);
19     }
20   }
21   return result
22 }

代码截图展示：