Is defining class variables as null required if they are going to be set during construct?

let say we have class Person($name), Does $name need to be asigned as null as such:

class Person{
    var $name = null;

    publ开发者_开发百科ic function __construct($name = null){
        $this->name = $name;
    }
}

Or can var $name = null be eliminated all together?

You can safely leave it as var $name;. null will be the default value anyway.

If you do not do var $name = null; and you try to access it before it is assigned you will get warnings/errors.

But in your case I do not see why it is needed, except for readability of the code (although you can add a comment about it)

It's usually better to declare the properties beforehand for documentation and IDEs' auto-complete functionality. However, it's not something that's required by PHP.

Also, unless you are worried about PHP4 (I hope not), it's more proper to use "public" instead of "var".