<?php // OK $a = 'a' . "b"; $b = true * "b"; $c = null + 2.2; $d = 'a' . strtolower("b"); $d = 'a' . rand("b"); // could do but needs 'determinist' functions $e = 2 << 3; $f = !(2 + 4 - 4); $g = (6 and 7); $h = 8 ^ 9; $h = 8 ** CONSTANTE; $i = 'a' . Stdclass::c; // KOK $A = 'a' . $a; $B = __DIR__ + 1; $C = 'a' . $a->b; $E = 'a' . Stdclass::$D; $E = 'a' % Stdclass::D(); $E = 'a' >> $c->d();