PHP Program Find Intersection between Two array

Create PHP  function FindIntersection(strArr) read the array of strings stored in strArr which will contain 2 element

 the first element will represent a list of comma-separated numbers sorted in ascending order.
 the second element will represent a second list of comma-separated numbers. 

Your function should return a comma-separated string containing the numbers that occur in elements of strArr in sorted order.
  If there is no intersection, return the string false.

Solution:

  function FindIntersection($strArr) {
    $return ='false';  
    $array1 = explode(',',$strArr[0]);
    $array1= array_map('trim',$array1);

    $array2 = explode(',',$strArr[1]);
    $array2= array_map('trim',$array2);

    $result= array_intersect($array1,$array2);
    if(!empty($result)){
      $return=implode(',',$result);  
    }

  return $return;

}