What is the difference between PHP 4 and 5?

[UncleSam]

Could share with thoughts about the difference between PHP 4 and 5 versions.

[jthayne]

There is actually a pretty good description of it all at wikipedia.

[VIP]

I think that you can search this information in Google, it will give the best answer.

[UncleSam]

Thanks for your help. I will follow your advices.

[Maldrex]

Is it post filling? Use php.net to learn php.

[benivolent]

One important difference is that PHP4 is deprecated and won't be supported after a while, whereas PHP5 is not and will continue to receive updates after the developers abandon PHP4.

[markei]

I remember one important thing happened when I upgraded my servers from php4 to php5 - it broke my website pages that passed variables.

It was my own incomplete coding I guess, but it had worked fine until then.

After php5, I had to use $_GET and $_POST at the beginning of (or in the code of) any web page that I used passed variables on, or they would not be passed.

It was a major change in the way I coded pages, and, as I said, broke all my websites that passed variables from one page to another.

Hopefully it helps someone.

***On a side note, I also have noticed that with newer browsers, a lot of old javascript scripts are broken because they weren't written with semantic code, but code that "worked", so they have to be carefully gone over and rewritten as well.

[carolin]

in the object model in php4 we pass everything including objects also by value ..
in php5 we pass by reference..
php5 provides to use class constants and allows static properties or methods..
class metods and properties have visibility in php5