Numeric sort on an array with javascript

Question

I have this array :

[ [ 1, 'a' ], [ 2, 'b' ], [ 1, 'd' ], [ 9, 'e' ], [ 1, 'f' ], [ 11, 'g' ], [ 9, 'h' ], [ 3, 'i' ] ]

and I would like to have :

[ [ 11, 'g' ], [ 9, 'e' ], [ 9, 'h' ], [ 3, 'i' ], [ 2, 'b' ], [ 1, 'a' ], [ 1, 'd' ], [ 1, 'f' ] ]

How can I do that with javascript please ?

I tried sort(), I also tried with sort(compare) with :

function compare(x, y) {
  return x - y;
}

Answer 1

You can use .sort() with Array Destructuring like this:

function compare([a], [b]) {
  return b - a;
}

Demo:

let a = [ [ 1, 'a' ], [ 2, 'b' ], [ 1, 'd' ], [ 9, 'e' ], [ 1, 'f' ], [ 11, 'g' ], [ 9, 'h' ], [ 3, 'i' ] ];

a.sort(compare);

function compare([a], [b]) {
  return b - a;
}

console.log(a);

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---

In case first elements match, you can sort based on 2nd element as well:

function compare([a, c], [b, d]) {
  return (b - a) || c.localeCompare(d)
}

Demo:

let a = [ [ 2, 'b' ], [ 1, 'd' ], [ 9, 'e' ], [ 1, 'f' ], [ 11, 'g' ], [ 9, 'h' ], [ 3, 'i' ], [ 1, 'a' ] ];

a.sort(compare);

function compare([a, c], [b, d]) {
  return (b - a) || c.localeCompare(d);
}

console.log(a);

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Answer 2

You need to compare the first element in the nested array since you want to sort based on that number.

function compare(x, y) {
  return y[0] - x[0];
}

var data = [
  [1, 'a'],
  [2, 'b'],
  [1, 'd'],
  [9, 'e'],
  [1, 'f'],
  [11, 'g'],
  [9, 'h'],
  [3, 'i']
];

function compare(x, y) {
  return y[0] - x[0];
}

data.sort(compare);

console.log(data);

---

In case you want to sort based on second element(secondary sorting in case the first element is same) then use String#localeCompare method for comparing.

function compare(x, y) {
  return y[0] - x[0] || x[1].localeCompare(y[0]);
}

var data = [
  [2, 'b'],
  [1, 'd'],
  [9, 'e'],
  [1, 'f'],
  [1, 'a'],
  [11, 'g'],
  [9, 'h'],
  [3, 'i']
];

function compare(x, y) {
  return (y[0] - x[0]) || x[1].localeCompare(y[1]);
}

data.sort(compare);

console.log(data);

Answer 3

Compare the elements based on their first element, which is the number.

var a = [ [ 1, 'a' ], [ 2, 'b' ], [ 1, 'd' ], [ 9, 'e' ], [ 1, 'f' ], [ 11, 'g' ], [ 9, 'h' ], [ 3, 'i' ] ];

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

console.log(a)

Answer 4

Use sort to compare first element and if first element is same then compare the second element.

arr.sort( (a,b) => (b[0] - a[0]) || (b[1] - a[1]) )

Demo

var arr = [ [ 1, 'a' ], [ 2, 'b' ], [ 1, 'd' ], [ 9, 'e' ], [ 1, 'f' ], [ 11, 'g' ], [ 9, 'h' ], [ 3, 'i' ] ];

arr.sort( (a,b) => (b[0] - a[0]) || (b[1] - a[1]) );

console.log(arr);