Question

I’m a little confused by some PHP syntax I’ve come across. Here is an example:

$k = $this->_tbl_key;  if( $this->$k) {    $ret = $this->_db->updateObject( $this->_tbl, $this, $this->_tbl_key, $updateNulls ); } else {     $ret = $this->_db->insertObject( $this->_tbl, $this, $this->_tbl_key ); } 

My question is basically what does $this->$k mean? I figured it might mean the member variable that goes by the name of whatever is in $this->_tbl_key, but how would that work? Is it possible to add member variables to a class at run-time?

Answer 1

It’ll look up whatever the value of ‘k’ is, and treat it as a variable name. These two samples are the same:

echo ($obj->myvar);  ####  $k = 'myvar'; echo ($obj->$k);