使用 Javascript ES6 修改對象列表

Question

我有下面的對象數組，其中vertical作為字符串， projects作為其中的對象數組。 projects也可以是空的。 每個projects條目如果不為空，則將具有name和releaseType作為屬性。

[
  {
    "vertical": "Alpha",
    "projects": [
      {
        "name": "Test",
        "releaseType": ""
      }
    ]
  },
  {
    "vertical": "Beta",
    "projects": []
  },
  {
    "vertical": "Gamma",
    "projects": [
      {
        "name": "Lincoln",
        "releaseType": "Google Pay"
      },
      {
        "name": "Madison",
        "releaseType": "PayPal"
      }
    ]
  }
]

我想獲取以下格式的項目列表。 有人可以讓我知道如何實現這一目標。 這不是常規的過濾方法，但需要使用 map 進行一些操作。 我嘗試了一些東西，但我無法達到預期的結果。

[
  {
    "vertical": "Alpha",
    "feature": "Test",
     "releaseType": ""
  },
  {
    "vertical": "Gamma",
    "feature": "Lincoln",
     "releaseType": "Google Pay"
   },
   {
     "vertical": "Gamma",
     "feature": "Madison",
     "releaseType": "PayPal"
   }
]

Answer 1

您可以使用reduce來解決它

arr.reduce((pre, cur) => {
  if (cur.projects.length) {
    pre.push(...cur.projects.map(p => ({
      vertical: cur.vertical,
      feature: p.name,
      releaseType: p.releaseType,
    })))
  }

  return pre;
}, []);

Answer 2

您可以為此使用Array.reduce

let formattedProjects = arr.reduce((p, c, i, a) => {
    if (c.projects.length) {
        p = p.concat(c.projects.map(project => {
            return {
                vertical: c.vertical,
                feature: project.name,
                releaseType: project.releaseType
            }
        }));
    }

    return p;
}, []);

演示： https://jsfiddle.net/6zk8jhat/

Answer 3

Double flatMap ，應該很好地解決這個問題：

 const input = [{vertical:"Alpha",projects:[{name:"Test",releaseType:""}]},{vertical:"Beta",projects:[]},{vertical:"Gamma",projects:[{name:"Lincoln",releaseType:"Google Pay"},{name:"Madison",releaseType:"PayPal"}]}]; const res = input.flatMap(e => e.projects.flatMap(x => [{vertical: e.vertical, ...x}]) ) console.log(res)

 .as-console-wrapper { max-height: 100%;important: top; 0; } /* ignore this */

Answer 4

let arr = [
  {
    vertical: "Alpha",
    projects: [
      {
        name: "Test",
        releaseType: "",
      },
    ],
  },
  {
    vertical: "Beta",
    projects: [],
  },
  {
    vertical: "Gamma",
    projects: [
      {
        name: "Lincoln",
        releaseType: "Google Pay",
      },
      {
        name: "Madison",
        releaseType: "PayPal",
      },
    ],
  },
];

arr = arr
  .map((obj) => {
    return obj.projects.map((proj) => {
      return {
        vertical: obj.vertical,
        ...proj,
      };
    });
  })
  .flat();