How does this used to sort an array works?

Question

How does this code work? I dont understand how the minus is used. I'm using an Array of Objects. Is this how it works? If the value of B is lets say 10 and A is equal 20, 10 - 20 is -10. As it returns -10, it will come first.

player.sort((a,b)=> {
    return b.score - a.score;
});

[MDN Array.prototype.sort()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort) — crashmstr, May 20 '20 at 15:24
Does this answer your question? [How does Javascript's sort() work?](https://stackoverflow.com/questions/1494713/how-does-javascripts-sort-work) — ABGR, May 20 '20 at 15:28

Nafeo Alam · Answer 1 · 2020-05-20T17:27:11.820

If compareFunction is not supplied, all non-undefined array elements are sorted by converting them to strings and comparing strings in UTF-16 code units order. For example, "banana" comes before "cherry". In a numeric sort, 9 comes before 80, but because numbers are converted to strings, "80" comes before "9" in the Unicode order. All undefined elements are sorted to the end of the array.

Note : In UTF-16, Unicode characters above \uFFFF are encoded as two surrogate code units, of the range \uD800-\uDFFF. The value of each code unit is taken separately into account for the comparison. Thus the character formed by the surrogate pair \uD655\uDE55 will be sorted before the character \uFF3A.

If compareFunction is supplied, all non-undefined array elements are sorted according to the return value of the compare function (all undefined elements are sorted to the end of the array, with no call to compareFunction). If a and b are two elements being compared, then:

If compareFunction(a, b) returns less than 0, sort a to an index lower than b (i.e. a comes first). If compareFunction(a, b) returns 0, leave a and b unchanged with respect to each other, but sorted with respect to all different elements. Note: the ECMAscript standard does not guarantee this behavior, thus, not all browsers (e.g. Mozilla versions dating back to at least 2003) respect this. If compareFunction(a, b) returns greater than 0, sort b to an index lower than a (i.e. b comes first). compareFunction(a, b) must always return the same value when given a specific pair of elements a and b as its two arguments. If inconsistent results are returned, then the sort order is undefined. So, the compare function has the following form:

function compare(a, b) {
  if (a is less than b by some ordering criterion) {
    return -1;
  }
  if (a is greater than b by the ordering criterion) {
    return 1;
  }
  // a must be equal to b
  return 0;
}

To compare numbers instead of strings, the compare function can simply subtract b from a. The following function will sort the array in ascending order (if it doesn't contain Infinity and NaN):

function compareNumbers(a, b) {
  return a - b;
}

reference: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort

this looks to be copied verbatim from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort without any acknowledgement of doing so — Sam Mason, May 20 '20 at 17:23

How does this used to sort an array works?

1 Answers1