differences between PHP3 and PHP4
| From: | ASHIDA Naoyuki | Date: | Sat, 14 Oct 2000 07:54:48 +0000 |
| Subject: | differences between PHP3 and PHP4 | ||
| Groups: | php.general | ||
| Request: | Send a blank email to php-general+get-20132@lists.php.net to get a copy of this message | ||
Hi php-general,
I found the differences between PHP3 and PHP4.
If these are known issues, ignore them.
But they are not found in
http://www.php.net/version4/incompatibilities.php
Thanks a lot.
-----
(1) In ver.3, a function must be defined in the step
prior to the calling point.
e.g.
function aaa (){
bbb(); # resuls in syntax error in ver3;"hey!!" in ver4.
}
function bbb(){
echo "hey!!";
}
------
(2) In ver4, The scope of a constant defined in a
member-function can be reached from other
member-functions in the same class , unlike ver3.
e.g.
class Foo{
function aaa(){
define("LUCKY_NUMBER",777);
}
function bbb(){
echo LUCKY_NUMBER;
}
}
$foo = new Foo; # $foo = new Foo; is error in ver3 also
$foo->aaa();
$foo->bbb(); # echoes "777" in ver4; "LUCKY_NUMBER" in ver3
------
(3) isSet([an uninitialized instance var.])
returns false in ver 4; true in ver3
e.g
class Entity{
var $db;
function check_db(){
if(!isSet($this->db)){
$this->db = new MyDB; # never executed in ver3
}
}
}
---
(4) class name is case-sensitive in ver4, unlike ver3
------
Mr. Ashida, Naoyuki
Aurora Systems, Inc., Japan