Question 264343 in Javascript Question posted in
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Javascript – sort an array of arrays based on another array

How can I sort an array of arrays based on another array?

Example:

const dataset = [
  [ 'red', [{name: 'Apple car'}] ], 
  [ 'blue', [{name: 'Toothpiece'}] ],
  [ 'orange', [{name: 'Sun'}] ],
  [ 'yellow', [{name: 'Cat'}] ], 
] 
const order = ['blue', 'yellow', 'red', 'orange']

const sortedDataset = sortArrayBasedOnAnother(dataset, order)
// [
//   [ 'blue', [{name: 'Toothpiece'}] ],
//   [ 'yellow', [{name: 'Cat'}] ],
//   [ 'red', [{name: 'Apple car'}] ], 
//   [ 'orange', [{name: 'Sun'}] ],
// ]

This is what I tried but it doesn’t work:

function sortArrayBasedOnAnother(dataset, order) {
  return order.filter((value) => dataset[0].includes(value))
}

note: dataset is an array of arrays because it’s computed from groupBy of Lodash

Tags:

4

Answers


  1. 0

    I would try it like this:

    function sortArrayBasedOnAnother(dataset, order) {
  const colorIndexMap = {};
  for (let i = 0; i < order.length; i++) {
    colorIndexMap[order[i]] = i;
  }

  dataset.sort((a, b) => colorIndexMap[a[0]] - colorIndexMap[b[0]]);
  return dataset;
}

    The colorIndexMap maps the colors from the order array to their corresponding index positions. The sort() function expects a comparison function that takes two elements (a and b) from the array and returns a negative, zero, or positive value to determine the order. colorIndexMap[a[0]] retrieves the index position of the color in a, same with b. By subtracting these values, the comparison function determines the order: If the result is negative, it means that a should come before b. If it’s positive, b should come before a. If it’s zero, the order remains unchanged.

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  2. 0

    You can just use sort method and then use indexOf or each element from the order array to sort the dataset.

    const dataset = [
  [ 'red', [{name: 'Apple car'}] ], 
  [ 'blue', [{name: 'Toothpiece'}] ],
  [ 'orange', [{name: 'Sun'}] ],
  [ 'yellow', [{name: 'Cat'}] ], 
] 
const order = ['blue', 'yellow', 'red', 'orange']

dataset.sort(([a], [b]) => order.indexOf(a) - order.indexOf(b))

console.log(dataset)
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  3. 0

    Array.sort() can pass in a custom compare function then the custom function will check the positions of the elements in the second array and use that to determine the sorting order.

    function sortArrayBasedOnAnother(dataset, order) {
  dataset.sort((a, b) => {
    let indexA = order.indexOf(a[0]);
    let indexB = order.indexOf(b[0]);
    return indexA - indexB; //will return negative, 0, or positive value depending on their positions inorder array
  });
  return dataset;
}

    then calling the function with your dataset and order arrays and it will return the sorted dataset.

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  4. 0

    First create a "key → item" map so that you can retrieve items by their keys, then iterate the order array and use that map to build the result:

    const map = {};

for (let item of dataset) {
    map[item[0]] = item;
}

const result = [];

for (let key of order) {
    if (map[key]) {
        result.push(map[key]);
    }
}

    (alternatively, for map, you may consider to use a Map object rather than a plain object)

    Note that only items present in the order array will be included, i.e. if a key is missing from the order array, the corresponding item will not be included in the result.

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