PHP has several functions that deal with sorting arrays, and this document exists to help sort it all out.
The main differences are:
Function name | Sorts by | Maintains key association | Order of sort | Related functions |
---|---|---|---|---|
array_multisort() | value | associative yes, numeric no | first array or sort options | array_walk() |
asort() | value | yes | low to high | arsort() |
arsort() | value | yes | high to low | asort() |
krsort() | key | yes | high to low | ksort() |
ksort() | key | yes | low to high | asort() |
natcasesort() | value | yes | natural, case insensitive | natsort() |
natsort() | value | yes | natural | natcasesort() |
rsort() | value | no | high to low | sort() |
shuffle() | value | no | random | array_rand() |
sort() | value | no | low to high | rsort() |
uasort() | value | yes | user defined | uksort() |
uksort() | key | yes | user defined | uasort() |
usort() | value | no | user defined | uasort() |
Another way to do a case case-insensitive sort by key would simply be:
<?php
uksort($array, 'strcasecmp');
?>
Since strcasecmp is already predefined in php it saves you the trouble to actually write the comparison function yourself.
If you search a feature which sorts an array incasesensitive by key, try this:
<?php
function isort($a,$b) {
return strtolower($a)>strtolower($b);
}
uksort($array, "isort");
?>
If you need to perform any of these sort functions on an array containing two or more equivalent values, you can get the equivalents to fall next to each other within the overall ordering (similar to how MySQL's ORDER BY works...) instead of breaking the sort() function, by using ksort() as a second parameter to arbitrarily distinguish any equivalent values by their unique keys:
<?php
sort($array, ksort($array));
?>
Seems like this effect should be built in. At least the workaround is so short...