如何根據數組中對象的某個屬性值生成對應的多個數組

今天有個朋友問了我一個需求，她有個數組，需要根據數組中的type字段生成對應type相同的數組，而這個type是前端界面上動態添加獲得的，也不曾有碼表。

先上數組

var arr = [
    {regulationsId: 5172, title: "測試111標題2 ", type: 610, state: 1, createdTime: 1530152467000},
    {regulationsId: 5169, title: "測試111標題", type: 610, state: 1, createdTime: 1530085573000},
    {regulationsId: 5170, title: "測試123標題", type: 609, state: 1, createdTime: 1530085687000},
    {regulationsId: 5171, title: "測試1122標題", type: 608, state: 1, createdTime: 1530085750000}
];

可以發現這個需求就是數組的名稱要動態生成，奉上代碼如下：

var arr = [
    {regulationsId: 5172, title: "測試111標題2 ", type: 610, state: 1, createdTime: 1530152467000},
    {regulationsId: 5169, title: "測試111標題", type: 610, state: 1, createdTime: 1530085573000},
    {regulationsId: 5170, title: "測試123標題", type: 609, state: 1, createdTime: 1530085687000},
    {regulationsId: 5171, title: "測試1122標題", type: 608, state: 1, createdTime: 1530085750000}
];

//先獲取一下這個數組中有多少個type
var types = [];
for(var i in arr){
    if(types.indexOf(arr[i].type) === -1){
        types.push(arr[i].type)
    }
}
//一個包含多個list的結果對象
var obj = {};

// 根據type生成多個數組
for(var k in types){
    for(var j in arr){
        if(arr[j].type == types[k]){
            console.log(types[k], ">>>>>>>>>", arr[j])
            obj[types[k]] = obj[types[k]] || [];
            obj[types[k]].push(arr[j])
        }
    }
}
console.log(types)
console.log(obj)

解決方案如上，應該還有高逼格的實現方法，本人愚鈍，暫時想到這個方法。