Make you code works !!

function compareTriplets(a, b) { let output = [ 0 , 0 ] for ( let i = 0 ; i < a.length;i ++ ){ if (a[i] < b[i]) output[ 1 ] ++ else if (a[i] > b[i]) output[ 0 ] ++ } return output; }   for styling use http://hilite.me/