Question

我想比较node.js中对象的数组和数组，并基于比较生成一个新的json对象。在下面的代码中，我具有日期的“ dateList” 列表和具有json数组的结果，现在，我想比较dateList和结果，如果结果对象具有日期dateList的值，那么我们必须获取执行值，然后将其推入新数组；如果不相等，则必须推为0。

服务器代码：

var dateList = [
  "2018-08-01",
  "2018-07-31",
  "2018-07-30",
  "2018-07-29",
  "2018-07-28",
  "2018-07-27",
  "2018-07-26"
]
var result = [{
    CDate: '2018-07-31',
    executions: 1
  },
  {
    CDate: '2018-07-30',
    executions: 2
  },
  {
    CDate: '2018-07-27',
    executions: 3
  },
  {
    CDate: '2018-07-26',
    executions: 2
  }
];
var allList = [];

for (key in dateList) {
  for (keyResult in result) {
    if (dateList[key] === result[keyResult].CDate) {
      var obj = {
        "date": dateList[key],
        "value": result[keyResult].executions
      }
      allList.push(obj);
      break;
    } else {
      var obj = {
        "date": dateList[key],
        "value": 0
      }
      allList.push(obj)
      break;

    }
  }

}
console.log(allList);

当前输出：

[{
    "date": "2018-08-01",
    "value": 0
  },
  {
    "date": "2018-07-31",
    "value": 1
  },
  {
    "date": "2018-07-30",
    "value": 0
  },
  {
    "date": "2018-07-29",
    "value": 0
  },
  {
    "date": "2018-07-28",
    "value": 0
  },
  {
    "date": "2018-07-27",
    "value": 0
  },
  {
    "date": "2018-07-26",
    "value": 0
  }
]

预期输出：

[{
    "date": "2018-08-01",
    "value": 0
  },
  {
    "date": "2018-07-31",
    "value": 1
  },
  {
    "date": "2018-07-30",
    "value": 2
  },
  {
    "date": "2018-07-29",
    "value": 0
  },
  {
    "date": "2018-07-28",
    "value": 0
  },
  {
    "date": "2018-07-27",
    "value": 3
  },
  {
    "date": "2018-07-26",
    "value": 2
  }
]

请帮助

Answer 1

该else分支位于内部数组内部，但是，仅当内部循环未在0-entry中找到给定日期时才要推送result，只有在何时才能知道循环结束（新变量found对其进行了跟踪）：

var dateList = [
  "2018-08-01",
  "2018-07-31",
  "2018-07-30",
  "2018-07-29",
  "2018-07-28",
  "2018-07-27",
  "2018-07-26"
]
var result = [{
    CDate: '2018-07-31',
    executions: 1
  },
  {
    CDate: '2018-07-30',
    executions: 2
  },
  {
    CDate: '2018-07-27',
    executions: 3
  },
  {
    CDate: '2018-07-26',
    executions: 2
  }
];
var allList = [];

for (key in dateList) {
  var found=false;
  for (keyResult in result) {
    if (dateList[key] === result[keyResult].CDate) {
      var obj = {
        "date": dateList[key],
        "value": result[keyResult].executions
      }
      allList.push(obj);
      found=true;
      break;
    }// else {
  }
  if(!found){
    var obj = {
      "date": dateList[key],
      "value": 0
    }
    allList.push(obj)
    //break;
  }
}
console.log(allList);

另一种方法是在开头创建一个0-entry，然后从内部循环对其进行更新并在末尾进行推送：

var dateList = [
  "2018-08-01",
  "2018-07-31",
  "2018-07-30",
  "2018-07-29",
  "2018-07-28",
  "2018-07-27",
  "2018-07-26"
]
var result = [{
    CDate: '2018-07-31',
    executions: 1
  },
  {
    CDate: '2018-07-30',
    executions: 2
  },
  {
    CDate: '2018-07-27',
    executions: 3
  },
  {
    CDate: '2018-07-26',
    executions: 2
  }
];
var allList = [];

for (key in dateList) {
  var obj = {
    "date": dateList[key],
    "value": 0
  };
  for (keyResult in result) {
    if (dateList[key] === result[keyResult].CDate) {
      obj.value=result[keyResult].executions;
      break;
    }
  }
  allList.push(obj)
}
console.log(allList)

如何通过比较对象的array（date）和array生成json？

1 个答案: