#49524 [Bgs]: Inequalities example in SWITCH documentation
ID: 49524
User updated by: matt at plasmacoustics dot com
Reported By: matt at plasmacoustics dot com
Status: Bogus
Bug Type: Documentation problem
Operating System: WinXP SP3
PHP Version: 5.3.0
New Comment:
Dan:
There is another example, see
http://au.php.net/manual/en/control-structures.switch.php#93342
If $totaltime is ZERO, a confusing semantic error would result.
Reliance on the arbitrary argument being interpreted as TRUE seems
widespread.
Why not add a SWITCH example covering INEQUALITIES to the
documentation?
Previous Comments:
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[2009-09-12 02:01:59] matt at plasmacoustics dot com
Thanks for pointing out the errors. You're right, there are many
mistakes in the submission, do feel free to delete it.
I do maintain though that the SWITCH argument would be best as TRUE to
guarantee the expected behaviour instead of relying on the type
conversion.
jonybd at yahoo dot com has a note that deals with inequalities. An
official example would be well received if you so wished. Cheers.
------------------------------------------------------------------------
[2009-09-11 15:41:57] danbrown@php.net
Three things to point out:
1.) You posted the bug from a completely different page than the one to
which you make reference.
2.) You grossly misquoted the code of which you complained.
3.) You didn't test it yourself, because - if you had - you'd see that
it works as advertised.
------------------------------------------------------------------------
[2009-09-10 16:33:48] matt at plasmacoustics dot com
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
---
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