Javascript Algorithm Array Sort Merge Sort 4

function merge(left,right){
  
  var i = 0;  /* left partition index */
  var j = 0;  /* right partition index */
  var l = left.length + right.length;
  var k = 0;/*from  ww w  . ja v a2s.  c o  m*/
  var a = [];

  /* add sentinel values to the array */
  left.push(Number.MAX_VALUE);
  right.push(Number.MAX_VALUE);

  for( k=0; k<l;k+=1 ){
    /* takes the element from the left array */
    if( left[i]<=right[j] ){
      a.push( left[i] );
      i +=1;
    /* takes the element from the right array */
    }else{
      a.push( right[j] );
      j +=1;
    }
  }

  return a;
}

function mergeSort(a){
  var q = 0,
    l = 0,
    left,right;

  l = a.length;

  if( l < 2 ){
    return a;
  }

  q = Math.floor(l/2);
  left  = mergeSort(a.slice(0,q));
  right  = mergeSort(a.slice(q,l));
  a    = merge( left , right )
  return a;
}

var arr = [1,245,1,5,13,-1,-56,1235,-187,5,8,0,11,45];
arr = mergeSort( arr , 0 , arr.length );
console.log(arr);