如何按最接近的数字对数组进行排序

Question

I'm trying to sort an array by the closest item to a specific number

The following solution doesn't work in all cases, for no reason

 let array = [{"price":"6850000"},{"price":"6692301"},{"price":"6880000"},{"price":"6735100"},{"price":"6708900"},{"price":"7000000"}] var price = 6692300 const closestArray = array.sort((a, b) => { if (Math.abs(b.price - price) > Math.abs(a.price - price)) { return b.price } else { return a.price } }) console.log(closestArray)

IT works with this example:

 let array = [401,402,400,478,421,432] var price = 400 const closestArray = array.sort((a, b) => { if (Math.abs(b - price) < Math.abs(a - price)) { return b } }) console.log(closestArray);

Answer 1

In both cases you are returning a positive number. That is to say, in both cases you are returning >0 . Which means your code is really doing:

  if (Math.abs(b.price - price) > Math.abs(a.price - price)) {
      sort b before a
  } else {
      sort b before a
  }

Basically your if statement is not doing anything.

What you really want is:

  if (Math.abs(b.price - price) > Math.abs(a.price - price)) {
      return 1
  } else {
      return -1
  }

or

  if (Math.abs(b.price - price) > Math.abs(a.price - price)) {
      return -1
  } else {
      return 1
  }

depending on weather you want to sort ascending or descending.

Better yet you really should be doing:

return Math.abs(b.price - price) - Math.abs(a.price - price)

or

return Math.abs(a.price - price) - Math.abs(b.price - price)

Answer 2

I believe this works.

let array = [{"price":"6850000"},{"price":"6692301"},{"price":"6880000"},{"price":"6735100"},{"price":"6708900"},{"price":"7000000"}]

var price = 6692300;
const closestArray = array.sort((a, b) => {
    const distOne = a.price - price;
    const distTwo = b.price - price;
    return Math.abs(distOne) - Math.abs(distTwo);
});

console.log(closestArray);

Answer 3

What you were doing was that you were returning a price but that price was always greater than 0 which is supposed to return a number greater than 0 only if the second one, or b, should come first.

let array = [{"price":"6850000"},{"price":"6692301"},{"price":"6880000"},{"price":"6735100"},{"price":"6708900"},{"price":"7000000"}];

var price = 6692300;
const closestArray = array.sort((a, b) => {
  if (Math.abs(b.price - price) < Math.abs(a.price - price)) {
      return 1;
  } else if (Math.abs(b.price - price) > Math.abs(a.price - price)) {
      return -1;
  }
  return 0; // because they are equal in value and should have equal ordering
})

console.log(closestArray);