PHP $this variable

Question

I am reading some PHP code that I could not understand:

class foo {
  function select($p1, $dbh=null) {
    if ( is_null($dbh) )
        $dbh = $this->dbh         


        

Answer 1

PHP is not strict about requiring class property declarations.

• Upon assignation, the property is silently created.
• Reading from a non-existent property generates a Notice if E_STRICT is enabled.
• The default value for any undefined property is NULL