ReflectionParameter::getDefaultValueConstantName
  Returns the default value's constant name if default value is constant or null
  
 
  Description
  
   public string ReflectionParameter::getDefaultValueConstantName
    ( void
   )
  
  WarningThis function is
currently not documented; only its argument list is available.
 
  
 
  Parameters
  This function has no parameters.
  
 
  Return Values
  
   Returns string on success or NULL on failure.