How does the “Array dereferencing” work on a scalar value of type boolean/integer/float/string as of PHP version 7.2.0?

Question

I am using PHP 7.2. I come across the following note from the arrays chapter of PHP Manual

Array dereferencing a scalar value which is not a string s

Answer 1

They are referring to non-complex types such as int or float.

In your example you are using an array. So you don't see the issue.

The first pair of brackets is array-dereferencing on the array (1, 2222, 3), the second is array-dereferencing on an integer (2222) which always returns null.

Simplified:

This "fails silently" as in theory you should get an error from this, rather than just null.

Also happens with null, other than int, float, bool:

But works correctly instead with arrays and strings.

Answering your question, "How does the “Array dereferencing” work on a scalar value of type": It doesn't, it just returns null instead of returning an error of some sort.