javascriptarraysreorderlist

Rearrange array with new order using javascript


I have an array

const arr = [
   {label: 'a', width: 200},
   {label: 'b', width: 200},
   {label: 'c', width: 200},
   {label: 'd', width: 200},
   {label: 'e', width: 200}
];

given another array

const data = ['d', 'e', 'a', 'c', 'b'];

It need's to re-arrange first array based on the new data.

What function should I use in javascript?

Edit: Thank you for very interesting comments. But to make it more complicated, let's assume that data could also be not the full list of the first array.

const data = ['a', 'c'];

and it still should outcome the first array where first two elements are a & c, and remaining ones are b, d, e. Finished array should be in a list of a, c, b, d, e.


Solution

  • const sort = (arr = [], data = []) => {
      const indicesMap = data.reduce((map, e, i) => map.set(e, i), new Map);
      return [...arr].sort(({ label: a}, { label: b }) => {
        const indexA = indicesMap.get(a), indexB = indicesMap.get(b);
        return (indexA === undefined || indexB === undefined) 
          ? isNaN(indexA) - isNaN(indexB)
          : indexA - indexB;
      });
    }
    
    const arr = [ {label: 'a', width: 200}, {label: 'b', width: 200}, {label: 'c', width: 200}, {label: 'd', width: 200}, {label: 'e', width: 200} ];
    console.log( sort(arr, ['d', 'e']) );
    console.log( sort(arr, ['a', 'd']) );
    console.log( sort(arr, ['d', 'e', 'a', 'c', 'b']) );