我如何分类考虑大于和小于考虑？

Question

I need to have a sort on two strings take the > and < symbols into consideration. So, for example, the sort might look like

<20
<40
<100
0.1
10
1,000,000.75
>100
>1,000

So basically all the strings with < are first, followed by a normal sort, followed by all numbers with a > symbol. I'd also like the sort to respect the exact order shown (eg >100 appears before >1,000 when sorted low to high)

Here is my code that works without the symbols (sorting all rows in a table):

if ($this.hasClass('sort-mixed')) {
  sort_func = sort_mixed;
}
$rows.sort(sort_func);

function sort_mixed(a, b) {

  var val_a = $(a).children().eq(column_index).text();
  var val_b = $(b).children().eq(column_index).text();

  val_a = Number(val_a.toString().replace(/,/g, ""));
  val_b = Number(val_b.toString().replace(/,/g, ""));  

  if(val_a > val_b) {
    return 1 * sort_direction;
  }
  if(val_a < val_b) {
    return -1 * sort_direction;
  }
  return 0;
}

Answer 1

Here is not a complete solution but enough to get you started. We'll break the array into multiple parts, sort each part, then put the array back together.

 function toNumber(s) { return +s.replace(/[^0-9.]/g, '') } var arr = [ '<20', '>1,000', '1,000,000.75', '<40', '0.1', '10', '<100', '>100' ]; var lt = arr .filter(s => s.startsWith('<')) .map(s => s.slice(1)) .map(toNumber) .sort((a, b) => a - b) .map(n => '<' + n); var eq = arr .filter(s => !s.startsWith('>') && !s.startsWith('<')) .map(toNumber) .sort((a, b) => a - b) .map(n => '' + n); var gt = arr.filter(s => s.startsWith('>')) .map(s => s.slice(1)) .map(toNumber) .sort((a, b) => a - b) .map(n => '>' + n); console.log([].concat(lt, eq, gt)); 

Outputs:

["<20", "<40", "<100", "0.1", "10", "1000000.75", ">100", ">1000"]

Answer 2

Sort with a single comparator function:

const order = { regular: 1, reverse: -1 };
let sortOrder = order.regular;
let strings = ['0.1', '1,000,000.75', '10', '<100', '<20', '<40', '>1,000', '>100'];

function compare(a, b) {
   function toNum(str) { return +str.replace(/[^0-9.-]/g, ''); }
   function range(str) { return { '<': -1, '>': 1 }[str[0]] || 0; }
   const rangeA = range(a);
   const rangeB = range(b);
   const score = rangeA === rangeB ? toNum(a) - toNum(b) : rangeA - rangeB;
   return score * sortOrder;
   }

strings.sort(compare);

The function range() checks if the string starts with a '<' or '>' and sets a value that is used for sorting if the strings have different ranges. Otherwise, the strings are converted to numbers and simply sorted as numbers.

With the example input data, the resulting strings array is:

["<20", "<40", "<100", "0.1", "10", "1,000,000.75", ">100", ">1,000"]

Fiddle with the code:
https://jsfiddle.net/fxgt4uzm

Edited:
Added sortOrder .

Answer 3

Composition approach

// Sort function maker
// - create a sort fn based on two compare fns
//   {f}= primary
//   {g}= secondary
const sort = (f, g) => (a, b) => f(a,b) || g(a,b)

// Compare function maker
// - create a compare fn based on a weighting fn, {w}
const cmp_asc_of = (w) => (a, b) => w(a) - w(b)
const cmp_desc_of = (w) => (a, b) => w(b) - w(a)

// Weighting function
// - weight a given string, {string}, returns a number
const weight_op = (string) => ..
const weight_num = (string) => ..

// Then, create sort functions
const asc  = sort(cmp_asc_of(weight_op), cmp_asc_of(weight_num))
const desc = sort(cmp_asc_of(weight_op), cmp_desc_of(weight_num))

// Usage
array.sort(asc)
array.sort(desc)

Demo

For your case..

..
function sort_mixed(a, b) {
  var val_a = ..
  var val_b = ..
  return isHighToLow ? desc(val_a, val_b) : asc(val_a, val_b)