插入一个新的 object 到阵列 Ramda

Question

Ramda 有插入 function 。 但就我而言，我不知道如何钻取 object 并将新的 object 插入到数组中。 还有一个新的 object 应该在数组的最后一个索引上，我们可以通过stuff["31"].length得到它。 我的尝试太可悲了，所以我决定不展示它们：/

数据 model：

const stuff = {
  "31": [
    {
      "id": "11",
      "title": "ramda heeeelp"
    },
    {
      "id": "12",
      "title": "ramda 123"
    },
    //HERE I WANT TO INSERT A NEW OBJECT - {id: "13", title: "new title"}
  ],
  "33": [
    {
      "id": "3",
      "title": "..."
    }
  ],
  "4321": [
    {
      "id": "1",
      "title": "hello world"
    }
  ]
}

Answer 1

这是一个简单的镜头使用， append添加到最后。

这是我的做法：

 const addObjToGroup = (groupId, newObj, data) => over (lensProp (groupId), append (newObj), data) const stuff = {"31": [{"id": "11", "title": "ramda heeeelp"}, {"id": "12", "title": "ramda 123"}], "33": [{"id": "3", "title": "..."}], "4321": [{"id": "1", "title": "hello world"}]} console.log ( addObjToGroup ('31', {id: "13", title: "new title"}, stuff) )

 <script src="//cdnjs.cloudflare.com/ajax/libs/ramda/0.26.1/ramda.js"></script> <script>const {over, lensProp, append} = R </script>

Answer 2

您还可以使用 Evolution to append 将该项目添加到groupId中的数组中：

 const { evolve, append } = R const addObjToGroup = (groupId, newObj) => evolve({ [groupId]: append(newObj) }) const stuff = {"31": [{"id": "11", "title": "ramda heeeelp"}, {"id": "12", "title": "ramda 123"}], "33": [{"id": "3", "title": "..."}], "4321": [{"id": "1", "title": "hello world"}]} const result = addObjToGroup ('31', {id: "13", title: "new title"})(stuff) console.log (result)

 <script src="//cdnjs.cloudflare.com/ajax/libs/ramda/0.26.1/ramda.js"></script>

Answer 3

R.useWith在这里也有帮助！

 const appendTo = R.useWith(R.over, [ R.lensProp, R.append, R.identity ]); // --- const stuff = { "31": [ { "id": "11", "title": "ramda heeeelp" }, { "id": "12", "title": "ramda 123" }, //HERE I WANT TO INSERT A NEW OBJECT - {id: "13", title: "new title"} ], "33": [ { "id": "3", "title": "..." } ], "4321": [ { "id": "1", "title": "hello world" } ] } console.log( appendTo('31', 'HELLO WORLD', stuff), );

 <script src="https://cdnjs.cloudflare.com/ajax/libs/ramda/0.26.1/ramda.js" integrity="sha256-xB25ljGZ7K2VXnq087unEnoVhvTosWWtqXB4tAtZmHU=" crossorigin="anonymous"></script>