js数据分组

var arr = [{
    "id": "1001",
    "name": "同学1",
    "value": "jack"
},
{
    "id": "1001",
    "name": "同学1",
    "value": "tom"
},
{
    "id": "1002",
    "name": "同学2",
    "value": "mike"
},
{
    "id": "1002",
    "name": "同学2",
    "value": "lily"
},
{
    "id": "1002",
    "name": "同学2",
    "value": "joe"
},
{
    "id": "1003",
    "name": "同学3",
    "value": "harry"
}
];
function handleGroup(arr) {
    let obj = {};
    let groups = [];
    arr.forEach(item => {

        if (!obj[item.id]) { //根据id分组
            groups.push({
                groupName: item.id,
                items: [item]
            });
            obj[item.id] = item;
        } else {

            groups.find(v => {//选择符合条件的第一个元素
                if (v.groupName === item.id) {
                    v.items.push(item);
                }
            });


        }
    });
    return groups;
}

console.log(handleGroup(arr));