#49524 [NEW]: Misleading user note in SWITCH documentation
From: matt at plasmacoustics dot com
Operating system: WinXP SP3
PHP version: 5.3.0
PHP Bug Type: Documentation problem
Bug description: Misleading user note in SWITCH documentation
Description:
------------
I feel the documentation on SWITCH might best include the appropriate code
for dealing with inequalities in a CASE, using switch(TRUE), because people
are posting User Notes with incorrect implementations.
Eg from: sedativchunk at gmail dot com
<?php
$rand=rand(1,50);
switch($randomizer) {
case ($randomizer <= 20):
$font_size = "11";
break;
}
?>
This isn't how switch() works! This will compare the value of
($randomizer) with the value of the inequality ($randomizer <= 20), right?
Here is a better example of why it strikes me as dangerous:
<?php
$zero=0;
switch($zero) {
case($zero > 1):
print '0 > 1? No!';
break;
}
?>
The above code will go into the case because it sees:
$zero[FALSE] == ($zero > 1)[also FALSE], leading to great coder
confusion.
The ACTUAL desired behaviour should be implemented with the code:
<?php
$zero=0;
switch(TRUE) {
case($zero > 1):
print '0 > 1? No!';
break;
}
?>
Could we add an inequality example to the documentation and mend the
user-contributed note #88643?
Reproduce code:
---------------
---
From manual page: language.operators.comparison
---
--
Edit bug report at http://bugs.php.net/?id=49524&edit=1
--
Try a snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=49524&r=trysnapshot52
Try a snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=49524&r=trysnapshot53
Try a snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=49524&r=trysnapshot60
Fixed in SVN: http://bugs.php.net/fix.php?id=49524&r=fixed
Fixed in SVN and need be documented: http://bugs.php.net/fix.php?id=49524&r=needdocs
Fixed in release: http://bugs.php.net/fix.php?id=49524&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=49524&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=49524&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=49524&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=49524&r=support
Expected behavior: http://bugs.php.net/fix.php?id=49524&r=notwrong
Not enough info: http://bugs.php.net/fix.php?id=49524&r=notenoughinfo
Submitted twice: http://bugs.php.net/fix.php?id=49524&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=49524&r=globals
PHP 4 support discontinued: http://bugs.php.net/fix.php?id=49524&r=php4
Daylight Savings: http://bugs.php.net/fix.php?id=49524&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=49524&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=49524&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=49524&r=float
No Zend Extensions: http://bugs.php.net/fix.php?id=49524&r=nozend
MySQL Configuration Error: http://bugs.php.net/fix.php?id=49524&r=mysqlcfg
Thread (9 messages)
- matt at plasmacoustics dot com