JavaScript 获取两个数组的交集

JavaScript 获取两个数组的交集，传入的数组必须是已经排过序的

/* finds the intersection of 
 * two arrays in a simple fashion.  
 *
 * PARAMS
 *  a - first array, must already be sorted
 *  b - second array, must already be sorted
 *
 * NOTES
 *
 *  Should have O(n) operations, where n is 
 *    n = MIN(a.length(), b.length())
 */
function arrayIntersection(a, b)
{
  var ai=0, bi=0;
  var result = new Array();
  while( ai < a.length && bi < b.length )
  {
     if      (a[ai] < b[bi] ){ ai++; }
     else if (a[ai] > b[bi] ){ bi++; }
     else /* they're equal */
     {
       result.push(a[ai]);
       ai++;
       bi++;
     }
  }
  return result;
}
console.log(arrayIntersection([1,2,3],[2,3,4,5,6]));//[2,3]