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phpsyntaxphp-5.4

Direct access class member access with clone

As of PHP 5.4 we can use this kind of syntax:

$oYesterday = (new \DateTime())->modify('-1 day');

So we don't have to create a temp variable. I was wondering why it doesn't work with clone, it leads to a parse error:

$oDayBefore = (clone $oYesterday)->modify('-1 day');

PHP Parse error:  syntax error, unexpected '->' (T_OBJECT_OPERATOR)
Solution

  • Because in PHP < 7, everything in the parser was essentially a hard-coded special case, and nobody has bothered to write the case for (clone $var). PHP 7 finally sports a real AST, where such things are possible.