$p = $p = = "? "1": $p; what's wrong with defining variables?

Why I run in the company is no problem, copy to my Computer, because my &p used as a page value, so I each function in $p first error.

Reply to discussion (solution)

Please ask the landlord p = $p = = "? "1": $p; Do you think this is a ternary operation?

$p = $p = = "? "1": $p;
There will be notice:undefined variable:p error warning
The reason is that you are not blocking E_notice level errors, that is to say: Your program is not robust

The loosely written wording is
$p = @ $p = = "? "1": $p;
The strict wording is
$p =! Isset ($p) | | $p = = "? "1": $p;

PHP7 can write
$p = $p?? "1";

Thank you 2L. Not so happy. $p solved the problem.
But there are a lot of notice:undefined problems. It turns out that the difference between computers is so big.

Program in error_reporting (e_all ^ e_notice);
PHP.ini in error_reporting = e_all ^ E_notice
After that, notice:undefined is gone.

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