Can I sort an array of objects based on a array of subarrays?-CodePudding

I would ask a question regarding sorting.

Let's say I have an array of objects:

let arrayToBeSorted = [
{
  name:"name1",
  id:"id1",
},
{
  name:"name2",
  id:"id2",
},
{
  name:"name3",
  id:"id3",
},
{
  name:"name4",
  id:"id4",
},
{
  name:"name5",
  id:"id5",
},
{
  name:"name6",
  id:"id6",
}];

And Let's say I have an array of sub arrays which each one is containing IDs string like that:

let sortArray = [["id2", "id1"], ["id5"], ["id6","id3","id4"]]

What I want to do is to sort the arrayToBeSorted based on the sortArray preserving each subarrays (in order to maintain an hermetic order)

This is the wanted result:

arrayToBeSorted = [
{
  name:"name2",
  id:"id2",
},
{
  name:"name1",
  id:"id1",
},
{
  name:"name5",
  id:"id5",
},
{
  name:"name6",
  id:"id6",
},
{
  name:"name3",
  id:"id3",
},
{
  name:"name4",
  id:"id4",
}];

EDIT: I tried to:

arrayToBeSorted.sort((a,b)=> for(var i=0; i<sortArray.length;i  ) 
{
   sortArr.indexOf(a.item.id) - sortArr.indexOf(b.item.id)
});

I also thought of sorting by each array and the concat the sorted result, but no success...

Thanks!

CodePudding user response：

You seem to be overcomplicating the sort operation here. Use sort() on arrayToBeSorted and get the indexOf each array element in a flat()tened copy of sortArray:

let arrayToBeSorted = [{
  name: "name1",
  id: "id1",
}, {
  name: "name2",
  id: "id2",
}, {
  name: "name3",
  id: "id3",
}, {
  name: "name4",
  id: "id4",
}, {
  name: "name5",
  id: "id5",
}, {
  name: "name6",
  id: "id6",
}];

let sortArray = [
  ["id2", "id1"],
  ["id5"],
  ["id6", "id3", "id4"]
];

console.log(arrayToBeSorted.sort((a, b) => sortArray.flat().indexOf(a.id) - sortArray.flat().indexOf(b.id)));

CodePudding user response：

You could flat the array and build an object with wanted order and sort the array.

const
    data = [{ name: "name1", id: "id1" }, {  name: "name2", id: "id2" }, { name: "name3", id: "id3" }, { name: "name4", id: "id4" }, { name: "name5", id: "id5" }, { name: "name6", id: "id6" }],
    sortArray = [["id2", "id1"], ["id5"], ["id6", "id3", "id4"]],
    order = Object.fromEntries(sortArray.flat().map((k, i) => [k, i   1]));

data.sort((a, b) => order[a.id] - order[b.id]);

console.log(data);

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CodePudding user response：

You can use sort() based on a flattened sortArray using findIndex() or indexOf() as @esqew. You could also go a step further and pre-process sortArray and create an object ids as keys and indices of sortArray as values. Then the sort function would be based on the object as follows:

let arrayToBeSorted = [{
        name: "name1",
        id: "id1",
    },
    {
        name: "name2",
        id: "id2",
    },
    {
        name: "name3",
        id: "id3",
    },
    {
        name: "name4",
        id: "id4",
    },
    {
        name: "name5",
        id: "id5",
    },
    {
        name: "name6",
        id: "id6",
    }
];

let sortArray = [["id2", "id1"], ["id5"], ["id6","id3","id4"]];

const flatO = Object.fromEntries( sortArray.flat().map((id,i) => [id,i]) );

const sortedArray = arrayToBeSorted.sort((a,b) => flatO[a.id] - flatO[b.id]);

console.log( sortedArray );

NOTE: This is equivalent to @NinaScholz's solution. Saw it just after I posted this. I have upvoted both @NinaScholz's and @esqew's solutions but I would take @NinaScholz's since the flat() method including the creation of the order object execute JUST ONCE.