calculate the median of an array with javascript

median.js

function median(values) {

    values.sort( function(a,b) {return a - b;} );

    var half = Math.floor(values.length/2);

    if(values.length % 2)
        return values[half];
    else
        return (values[half-1] + values[half]) / 2.0;
}

var list1 = [3, 8, 9, 1, 5, 7, 9, 21];
median(list1);

@danielbayerlein sort will mutate the array. I used the spread operator to instead return a new shallow copy. Before the spread operator concat and slice did the trick:

arr.concat().sort()
# or
arr.slice(0).sort()

Some more discussion on this topic https://stackoverflow.com/questions/9592740/how-can-you-sort-an-array-without-mutating-the-original-array

@sqren Thank you for the explanation.

@danielbayerlein You are welcome.
Btw. Noticed your project https://github.com/danielbayerlein/git-pick. I've create a tool called backport: https://github.com/sqren/backport

Looks like we are doing something similar :D

I would also check the length first. if it is zero return. no need to proceed further.