Javascript：根据另一个数组对大型多维数组重新排序

Question

I have a multidimensional array that behaves like a spreadsheet. First item it's a column header:

[
    ['A', 'B', 'C', 'D'],
    [ 1 ,  2 ,  3 ,  4 ],
    [ 5 ,  6 ,  7 ,  8 ],
    [...]
]

Order of the "columns" is defined by another array:

['C', 'A', 'D', 'B']

Expected result is:

[
    ['C', 'A', 'D', 'B'],
    [ 3 ,  1 ,  4 ,  2 ],
    [ 7 ,  5 ,  8 ,  6 ],
    [...]
]

Would .map , .splice and .indexOf be the best approach? What about their performance on a 20k+ array?

Thanks!

Answer 1

 function reorder(data, order) { let header = data[0]; let orderIndex = order.map(i => header.indexOf(i)); return data.map(row => orderIndex.map(i => row[i])); } let data = [ ['A', 'B', 'C', 'D'], [ 1 , 2 , 3 , 4 ], [ 5 , 6 , 7 , 8 ], ]; let order = ['C', 'A', 'D', 'B']; console.log(reorder(data, order)); 

As for performance... you'll need to test it.