To create a new object, use the new statement to instantiate a class:
<?php
class foo
{
    function do_foo()
    {
        echo "Doing foo."; 
    }
}
$bar = new foo;
$bar->do_foo();
?>
For a full discussion, see the Classes and Objects chapter.
   If an object is converted to an object, it is not
   modified. If a value of any other type is converted to an
   object, a new instance of the stdClass
   built-in class is created. If the value was NULL, the new instance will be
   empty. Arrays convert to an object with properties
   named by keys, and corresponding values. For any other value, a member
   variable named scalar will contain the value.
  
<?php
$obj = (object) 'ciao';
echo $obj->scalar;  // outputs 'ciao'
?>