Validation::comparison PHP Method

    public static function comparison($value1, $operator, $value2)
    {
        switch ($operator) {
            case '>':
            case 'greater':
                return $value1 > $value2;
            case '<':
            case 'less':
                return $value1 < $value2;
            case '>=':
            case 'greaterorequal':
                return $value1 >= $value2;
            case '<=':
            case 'lessorequal':
                return $value1 <= $value2;
            case '==':
            case 'equal':
                return $value1 == $value2;
            case '!=':
            case 'notequal':
                return $value1 != $value2;
        }
        return false;
    }

 function field_comparison($check1, $operator, $field2)
 {
     foreach ($check1 as $key => $value1) {
         $value2 = $this->data[$this->alias][$field2];
         if (!Validation::comparison($value1, $operator, $value2)) {
             return false;
         }
     }
     return true;
 }