find-int-odd.js

// Find the Odd Int
/*
Given an array of integers, find the one that appears an odd number of times.

There will always be only one integer that appears an odd number of times.
*/

const findOdd = a => a.find((number) => a.filter((n) => number === n).length % 2)

/* 
[7] should return 7, because it occurs 1 time (which is odd).
[0] should return 0, because it occurs 1 time (which is odd).
[1,1,2] should return 2, because it occurs 1 time (which is odd).
[0,1,0,1,0] should return 0, because it occurs 3 times (which is odd).
[1,2,2,3,3,3,4,3,3,3,2,2,1] should return 4, because it appears 1 time (which is odd).
 
// tests pass

*/