Js在数组中添加元素
如何提取数组中的字段，然后添加新的字段，获取数据如下：
```
var data = [
{"id":"1","name":"华为","data":"25u6s8f545d3"},
{"id":"2","name":"小米","data":"cd58de9d3c5d"},
];
```
我想获得的数据格式如下：
```
var data = [
{"id":"1","name":"华为","data":"25u6s8f545d3","mac":"25:u6:s8:f5:45:d3"},
{"id":"2","name":"小米","data":"cd58de9d3c5d","mac":"cd:58:de:9d:3c:5d"},
];
```
我现在方法如下：
```
for (var i = 0; i < data.length; i++) {
    var mac = data[i].data.toUpperCase();
        mac1 = mac.substring(0, 2);
        mac2 = mac.substring(2, 4);
        mac3 = mac.substring(4, 6);
        mac4 = mac.substring(6, 8);
        mac5 = mac.substring(8, 10);
        mac6 = mac.substring(10, 12);
        var mac = mac1 + ':' + mac2 + ':' + mac3 + ':' + mac4 + ':' + mac5 + ':' + mac6;
        data[i].mac = mac;
 };
```
请教下有没有更好的方法？我觉得自己方法有点烂。
```
var data = [
  { "id": "1", "name": "华为", "data": "25u6s8f545d3" },
  { "id": "2", "name": "小米", "data": "cd58de9d3c5d" },
];
data.forEach(item => {
  item.mac = item.data.replace(/\w{2}\B/g, '$&:')
})
console.log(data)
```