Created
August 23, 2011 19:34
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calculate the median of an array with javascript
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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); |
@sqren Otherwise you answer was good but the number sorting didn't work
This version will work!
function median(numbers: number[]) {
const middle = (numbers.length + 1) / 2;
const sorted = [...numbers].sort((a, b) => a - b); // you have to add sorting function for numbers
const isEven = sorted.length % 2 === 0;
return isEven ? (sorted[middle - 1.5] + sorted[middle - 0.5]) / 2 : sorted[middle - 1];
}
@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.
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@sqren, Thanks, worked like a charm.