How to get biggest array element based on his second sub array value

Question

I have an JavaScript array of arrays:

[[-786, 2], [-783, 1], [-782, 5], [-781, 1], [-779, 2], [-778, 1], [-775, 1], [-774, 1], [-773, 1], [-771, 2], [-769, 1], [-767, 1], [-766, 1], [-763, 2], [-760, 2]]

How can I get the biggest element based on value of second element in sub array?

In case above I want to get element:

[-782, 5]

Because 5 is biggest second value in all sub arrays. If there will more than one sub arrays with the bigger second value, I'd like to get first one.

Mariusz

Have you checked this answer? http://stackoverflow.com/questions/5052673/jquery-min-max-property-from-array-of-elements — Kye, Aug 22 '13 at 06:48

c.P.u1 · Accepted Answer · 2020-06-04T12:27:11.797

3

Perform a descending sort based on the second element of each element of the array.

var array = [[-786, 2], [-783, 1], [-782, 5], [-781, 1], [-779, 2], [-778, 1], [-775, 1], [-774, 1], [-773, 1], [-771, 2], [-769, 1], [-767, 1], [-766, 1], [-763, 2], [-760, 2]];


array.sort(function(a, b) {
    return b[1] - a[1];
});

console.log(array[0]);

jsFiddle Demo

Please note that while this solution is terse, using sort just for finding the largest or smallest element would be much slower than a for loop that finds the largest/smallest element in a single iteration.

edited Jun 04 '20 at 12:27

answered Aug 22 '13 at 06:55

c.P.u1

16,664
6
46
41

In an interview your will not be allowed to use **sort** , it is also highly not recommended to use sort as it is very slow. – Andy Nov 13 '17 at 01:02

score 1 · Answer 2 · answered Aug 22 '13 at 06:51

var array = [[-786, 2], [-783, 1], [-782, 5], [-781, 1], [-779, 2], [-778, 1], [-775, 1], [-774, 1], [-773, 1], [-771, 2], [-769, 1], [-767, 1], [-766, 1], [-763, 2], [-760, 2]];
var maxElementIndex = 0;
for (var i = 0; i < array.length; i++) {
    if (array[i][1] > array[maxElementIndex][1]) {
        maxElementIndex = i;
    }
}

console.log(array[maxElementIndex]);

score 1 · Answer 3 · answered Jun 05 '20 at 07:44

Since this is tagged d3 you could also use d3.greatest() from the d3-array module v2.3.0 (emphasis mine):

Returns the greatest element of the specified iterable according to the specified comparator or accessor.

By providing an accessor function that returns the second element from each element's array d3.greatest() will return the element having the greatest value comparing all second elements.

const data = [[-786, 2], [-783, 1], [-782, 5], [-781, 1], [-779, 2], [-778, 1], [-775, 1], [-774, 1], [-773, 1], [-771, 2], [-769, 1], [-767, 1], [-766, 1], [-763, 2], [-760, 2]];

const greatest= d3.greatest(data, d => d[1]);

console.log(greatest);

<script src="https://cdn.jsdelivr.net/npm/d3-array@2.4.0/dist/d3-array.min.js"></script>

Note, however, that at the time of writing d3.greatest() is not yet part of the D3 v5 main bundle, you have you use the d3-array module. It should be included in the upcoming v6, though.

score 0 · Answer 4 · answered Aug 22 '13 at 06:56

var target = [[-786, 2], [-783, 1], [-782, 5], [-781, 1], [-779, 2], [-778, 1], [-775, 1], [-774, 1], [-773, 1], [-771, 2], [-769, 1], [-767, 1], [-766, 1], [-763, 2], [-760, 2]]
var max = 0, tmp = 0;
var max_entry, tmp_entry;
while (target.length > 0){
  tmp_entry = target.pop();
  tmp = tmp_entry[1];
  if (tmp > max){
      max = tmp;
      max_entry = tmp_entry;
  }
}
alert(max_entry);

How to get biggest array element based on his second sub array value

4 Answers4