对数组进行排序

While this may seem obvious, user-defined array sorting functions ( uksort(), uasort(), usort() ) will *not* be called if the array does not have *at least two values in it*.The following code:                        <?phpfunction usortTest($a, $b) {    var_dump($a);    var_dump($b);    return -1;}$test = array('val1');usort($test, "usortTest");$test2 = array('val2', 'val3');usort($test2, "usortTest");?>Will output: string(4) "val3"string(4) "val2"The first array doesn't get sent to the function.Please, under no circumstance, place any logic that modifies values, or applies non-sorting business logic in these functions as they will not always be executed.

Another way to do a case case-insensitive sort by key would simply be:<?phpuksort($array, 'strcasecmp');?>Since strcasecmp is already predefined in php it saves you the trouble to actually write the comparison function yourself.