javascript - AngularJS 在属性数组中组合对象

Question

我有一大堆对象 (1500+)，这些对象在其中一个属性上匹配。因此可以减少对象的总数，例如为了在 ng-repeat 中获得更好的性能。我是 AngularJS 和 JS 本身的新手，非常感谢您的帮助!

我的对象数组(简化)

myArray = [
    {
        "role": "user111",
        "operation": "create",
        "concept": "folder"
    },
    {
        "role": "user111",
        "operation": "create",
        "concept": "task"
    },
    {
        "role": "user111",
        "operation": "delete",
        "concept": "task"
    },
    {
        "role": "user222",
        "operation": "create",
        "concept": "folder"
    },
    {
        "role": "user222",
        "operation": "create",
        "concept": "task"
    },
    {
        "role": "user222",
        "operation": "delete",
        "concept": "task"
    }
]

期望的输出

dreamArray = [
    {
        "role": "user111",
        "operation": {
               "create": ["folder", "task"],
               "delete": ["task"]
                      }
    },
    {
        "role": "user222",
        "operation": {
                   "create": ["folder", "task"],
                   "delete": ["task"]
                      }
    }
]

Answer 1

您可以使用 forEach() 循环和 thisArg 参数来做到这一点。

var myArray = [{"role":"user111","operation":"create","concept":"folder"},{"role":"user111","operation":"create","concept":"task"},{"role":"user111","operation":"delete","concept":"task"},{"role":"user222","operation":"create","concept":"folder"},{"role":"user222","operation":"create","concept":"task"},{"role":"user222","operation":"delete","concept":"task"}]

var result = [];
myArray.forEach(function(e) {
  if(!this[e.role]) {
   this[e.role] = {role: e.role, operation: {[e.operation]: [e.concept]}}
    result.push(this[e.role]);
  } else {
    var op = this[e.role].operation[e.operation]
    if(op) op.push(e.concept)
    else this[e.role].operation[e.operation] = [e.concept]
  }
}, Object.create(null))


console.log(result)