How to get the min and max of an array of numbers in javascript?

Question

What is the best way to get the min and max of an array into two variables? My current method feels lengthy:

var mynums = [0,0,0,2,3,4,23,435,343,23,2,34,34,3,34,3,2,1,0,0,0]
var minNum = null;
var maxNum = null;
for(var i = 0; i < mynums.length; i++) {
  if(!minNum) {
    minNum = minNum[i];
    maxNum = maxNum[i];
  } else if (mynums[i] < minNum) {
    minNum = mynums[i];
  } else if (mynums[i] > minNum && mynums[i] > maxNum) {
    maxNum = mynums[i]
  }
}

Other posts that appear to 'address' this seem to be old and I feel like there must be a better way in 2017.

Possible duplicate of [JavaScript: min & max Array values?](http://stackoverflow.com/questions/1669190/javascript-min-max-array-values) — Dave, Apr 24 '17 at 22:17

NS0 · Accepted Answer · 2017-04-24T22:18:19.490

5

You can just use Math.max() and Math.min()

For an array input, you can do

var maxNum = Math.max.apply(null, mynums);

var minNum = Math.min.apply(null, mynums);

edited Apr 24 '17 at 22:18

answered Apr 24 '17 at 22:16

NS0

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1
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var mynums = [0,0,0,2,3,4,23,435,343,23,2,34,34,3,34,3,2,1,0,0,0]; Math.max(mynums); // that returns a NaN. – Rolando Apr 24 '17 at 22:18
1

Added a solution for an array. – NS0 Apr 24 '17 at 22:18
Why is it that you have to use apply/null? – Rolando Apr 24 '17 at 22:24
`.apply` passes a this reference and an array of arguments to the method you use it on. When you `.apply(null, mynums)` you pass each value in the array as an argument to the Math.max() function. – Kyle Richardson Apr 24 '17 at 22:26
Most elegant in this day and age. – Rolando Apr 25 '17 at 01:16

Nenad Vracar · Answer 2 · 2017-04-24T22:29:17.590

0

You can use reduce() and find both min and max at the same time.

var mynums = [0, 0, 0, 2, 3, 4, 23, 435, 343, 23, 2, 34, 34, 3, 34, 3, 2, 1, 0, 0, 0]

var {min, max} = mynums.reduce(function(r, e, i) {
  if(i == 0) r.max = e, r.min = e;
  if(e > r.max) r.max = e;
  if(e < r.min) r.min = e;
  return r;
}, {})

console.log(min)
console.log(max)

edited Apr 24 '17 at 22:29

answered Apr 24 '17 at 22:23

Nenad Vracar

118,580
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score 0 · Answer 3 · answered Apr 24 '17 at 22:58

As an alternative, use Lodash min and max functions.

var mynums = [0,0,0,2,3,4,23,435,343,23,2,34,34,3,34,3,2,1,0,0,0];
var minNum = _.min(mynums); // 0
var maxNum = _.max(maxNum); // 435

And take a look at minBy and maxBy functions which also could be very useful.

How to get the min and max of an array of numbers in javascript?

3 Answers3