Re: Undefined variables and the array append operator

> Le 29 mars 2022 à 21:44, Rowan Tommins <rowan.collins@gmail.com> a écrit : > > Hi all, > > If $foo is not defined, statements such as $foo += 1 and $foo .= 'blah' raise > "undefined variable" Warnings in PHP 8, and will throw Errors in PHP 9. However, the very > similar looking $foo[] = 1 succeeds silently. > > This seems odd to me, as "append to string" and "append to array" seem like > very similar operations, with most of the same use cases and possible bugs. > > Hi, There are various subcases to consider: (1) $x[] = 42; and $x['y'] = 42; where $x is undefined (2) $x[] = 42; and $x['y'] = 42; where $x is null (3) $x['y'][] = 42; and $x['y']['w'] = 42; where $x is an array, and $x['y'] is undefined. Of course, I agree that (1) should be an error. The case (3) is similar to (1), but I think it is more controversial to change. I bet that they are various places in my code that take advantage of that feature, although personally I don’t mind to write $x['y'] ??= [ ]; when needed. —Claude