访问可以为null的对象字段的更好方法

Question

I saw this line of code and I was asking myself the reason of this syntaxe

if(false && isset($_SESSION['new_user']) && $_SESSION['new_user'] == true)

Basically the context is if we have a new user we treat him differently than existing users.

My first guess is that is made to avoid search values in a null variable. So first he tests if there is a variable, and if there is he checks its value. Is that what he does?

But everything inside the same if statement.

My question is, if the first part of the if statement is false, the second part is not tested? Is this a good practice? or would be better to do like this:

if(($_SESSION['new_user']){
    if ($_SESSION['new_user'] == true){
        [...]
    }
}

Answer 1

Your interpretation is correct. When using &&(AND), if the first condition is not met, no other conditions will be checked.

So it doesn't matter how you format your if, as long as you understand how the code works.

However, in your first example the false will make sure the condition is never true. In this case it is pretty useless.