如何使用公共键合并属性数组

Question

如何使用underscore js实现下面的结果？

当前结果：

[
{Stats: "Number of virus", "Dec-2018": "1"},
{Stats: "Number of alerts", "Dec-2018": "2"},
{Stats: "Number of incidents", "Dec-2018": "1"},
{Stats: "Vulnerabilities", "Dec-2018": "6"},
{Stats: "Number of virus", "Nov-2018": "4"},
{Stats: "Number of alerts", "Nov-2018": "6"},
{Stats: "Number of incidents", "Nov-2018": "2"},
{Stats: "Vulnerabilities", "Nov-2018": "8"},
{Stats: "Number of virus", "Oct-2018": "2"},
{Stats: "Number of alerts", "Oct-2018": "2"},
{Stats: "Number of incidents", "Oct-2018": "5"},
{Stats: "Vulnerabilities", "Oct-2018": "2"},
]

预期结果：

[
{Stats: "Number of virus", Dec-2018: "1", "Nov-2018": "4", Oct-2018: "2"},
{Stats: "Number of alerts", Dec-2018: "2","Nov-2018": "6", Oct-2018: "2"},
{Stats: "Number of incidents", Dec-2018: "1", "Nov-2018": "2", Oct-2018: "5"},
{Stats: "Vulnerabilities", Dec-2018: "6", "Nov-2018": "8", Oct-2018: "2"}
]

Answer 1

您可以通过以下步骤实现。首先，使用 indexBy() 函数创建一个具有唯一 Stats 值的对象。之后，对于每个数据元素，扩展具有相同 Stats 值的那个。就是这样！

var data = [
{Stats: "Number of virus", "Dec-2018": "1"},
{Stats: "Number of alerts", "Dec-2018": "2"},
{Stats: "Number of incidents", "Dec-2018": "1"},
{Stats: "Vulnerabilities", "Dec-2018": "6"},
{Stats: "Number of virus", "Nov-2018": "4"},
{Stats: "Number of alerts", "Nov-2018": "6"},
{Stats: "Number of incidents", "Nov-2018": "2"},
{Stats: "Vulnerabilities", "Nov-2018": "8"},
{Stats: "Number of virus", "Oct-2018": "2"},
{Stats: "Number of alerts", "Oct-2018": "2"},
{Stats: "Number of incidents", "Oct-2018": "5"},
{Stats: "Vulnerabilities", "Oct-2018": "2"},
]

var indexed = _.indexBy(data, 'Stats');

_.each(data, function(elem) {
  var object = indexed[elem.Stats];
  if (object) _.extend(object, elem);
});

var result = Object.values(indexed);

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>

Answer 2

您可以这样使用 reduce and Object.values()：

let input=[{Stats:"Number of virus","Dec-2018":"1"},{Stats:"Number of alerts","Dec-2018":"2"},{Stats:"Number of incidents","Dec-2018":"1"},{Stats:"Vulnerabilities","Dec-2018":"6"},{Stats:"Number of virus","Nov-2018":"4"},{Stats:"Number of alerts","Nov-2018":"6"},{Stats:"Number of incidents","Nov-2018":"2"},{Stats:"Vulnerabilities","Nov-2018":"8"},{Stats:"Number of virus","Oct-2018":"2"},{Stats:"Number of alerts","Oct-2018":"2"},{Stats:"Number of incidents","Oct-2018":"5"},{Stats:"Vulnerabilities","Oct-2018":"2"}];

let merged = input.reduce((acc, o) => {
  acc[o.Stats] = { ...acc[o.Stats], ...o }
  return acc;
}, {})

console.log(Object.values(merged))

Answer 3

你可以使用 findIndex 和 reduce

const data = [
{Stats: "Number of virus", "Dec-2018": "1"},
{Stats: "Number of alerts", "Dec-2018": "2"},
{Stats: "Number of incidents", "Dec-2018": "1"},
{Stats: "Vulnerabilities", "Dec-2018": "6"},
{Stats: "Number of virus", "Nov-2018": "4"},
{Stats: "Number of alerts", "Nov-2018": "6"},
{Stats: "Number of incidents", "Nov-2018": "2"},
{Stats: "Vulnerabilities", "Nov-2018": "8"},
{Stats: "Number of virus", "Oct-2018": "2"},
{Stats: "Number of alerts", "Oct-2018": "2"},
{Stats: "Number of incidents", "Oct-2018": "5"},
{Stats: "Vulnerabilities", "Oct-2018": "2"},
]

const res = data.reduce((all, {
  Stats,
  ...rest
}) => {

  let found = all.findIndex(o => Stats === o.Stats);

  if (found > -1 ) {
    all[found] = { ...all[found],
      ...rest
    }
  } else {
    all.push({ ...{
        Stats,
        ...rest
      }
    })

  }
  return all
}, [])

console.log(res)

如何使用公共键合并属性数组

How to merge array of properties using common key

javascript

underscore.js