Bug #51765 [Bgs]: class constant has different setter behavior than global constant

Edit report at http://bugs.php.net/bug.php?id=51765&edit=1 ID: 51765 User updated by: colin at sheaff dot net Reported by: colin at sheaff dot net Summary: class constant has different setter behavior than global constant Status: Bogus Type: Bug Package: Class/Object related Operating System: Any PHP Version: Irrelevant New Comment: And yet the following works: define( 'FOO', 'foo' ); define( 'BAR', FOO . 'bar' ); class ThisWorks { const bar = BAR; } echo ThisWorks::bar; If class constants are really compile time dependent, why is it ok to set one to a global const value which is only evaluated at run time? Previous Comments: ------------------------------------------------------------------------ [2010-05-07 16:55:20] johannes@php.net Thank you for taking the time to write to us, but this is not a bug. Please double-check the documentation available at http://www.php.net/manual/ and the instructions on how to report a bug at http://bugs.php.net/how-to-report.php This is a limitation in the implementation. For the class constant we need a constant value at compile time and can't evaluate expressions. define() is a regular function, evaluated at run time and can therefore contain any value of any form. changing this would mean to add an execution phase in the compiler ... ------------------------------------------------------------------------ [2010-05-07 15:17:53] colin at sheaff dot net Description: ------------ Global constants can be set using string concatenation and other global constants. This is useful. Class constants cannot be set using string concatenation or any functions, although they can be set to a global constant, or another class constant. The difference in setter behavior is confusing and limits utility of class constants. Test script: --------------- define( 'FOO', 'foo' ); define( 'BAR', FOO . 'bar' ); echo BAR . PHP_EOL; class Foobar { const foo = 'foo'; const bar = self::foo . 'bar'; } echo Foobar::bar; Expected result: ---------------- foobar foobar Actual result: -------------- Parse error: syntax error, unexpected '.', expecting ',' or ';' on line 8 ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/bug.php?id=51765&edit=1