#45716 [Opn->Bgs]: Addition and minus operators do not work properly when appended to a string

ID: 45716 Updated by: derick@php.net Reported By: pasamio at gmail dot com -Status: Open +Status: Bogus Bug Type: Scripting Engine problem Operating System: Linux 2.6.5-7.191-smp PHP Version: 5.2.6 New Comment: 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 because of operator precedence, see: http://no2.php.net/manual/en/language.operators.php Previous Comments: ------------------------------------------------------------------------ [2008-08-05 07:39:52] pasamio at gmail dot com Description: ------------ When using a simple addition or minus operator that is prepended by a string and concatenated to it will fail to work properly if the string has a value. When the string is empty (e.g. '' or ' ') it will work properly. The multiplication and division functions operate appropriately. Reproduce code: --------------- <?php $x = 10; $i = 2; echo "Addition Test\n"; echo 'Test 1: '. $x + $i . "\n"; echo 'Test 2: '. ($x + $i) . "\n"; echo 'Test 3: '; echo $x + $i . "\n"; echo 'Test 4: '; echo ''. $x + $i ."\n"; echo "\n"; echo "Subtraction Test\n"; echo 'Test 1: '. $x - $i . "\n"; echo 'Test 2: '. ($x - $i) . "\n"; echo 'Test 3: '; echo $x - $i . "\n"; echo 'Test 4: '; echo 'x'. $x - $i ."\n"; echo "\n"; Expected result: ---------------- moffats@dev1:~/public_html/testing> php bug-minus.php Addition Test Test 1: 12 Test 2: 12 Test 3: 12 Test 4: 12 Subtraction Test Test 1: 8 Test 2: 8 Test 3: 8 Test 4: 8 Actual result: -------------- moffats@dev1:~/public_html/testing> php bug-minus.php Addition Test 2 Test 2: 12 Test 3: 12 Test 4: 12 Subtraction Test -2 Test 2: 8 Test 3: 8 Test 4: 8 ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=45716&edit=1