code for function

code

function retByOrder(var arr){
  return arr.sort((a,b) => (a.rank > b.rank) ? 1 : ((b.rank > a.rank) ? -1 : 0)); 
}

function retByAverage(){
  var it = arr.values();
  var avg=0;
  for(let i=0;i<arr.length;i++){
    avg = avg+it.next().value
  }
  avg=avg/arr.length;
  return avg;
}