我有以下数组:
$data = array(
array("firstname" => "Mary", "lastname" => "Johnson", "age" => 25),
array("firstname" => "Amanda", "lastname" => "Miller", "age" => 18),
array("firstname" => "James", "lastname" => "Brown", "age" => 31),
array("firstname" => "Patricia", "lastname" => "Williams", "age" => 7),
array("firstname" => "Michael", "lastname" => "Davis", "age" => 43),
array("firstname" => "Sarah", "lastname" => "Miller", "age" => 24),
array("firstname" => "Patrick", "lastname" => "Miller", "age" => 27)
);
和以下排序函数:
function sortArray($data, $field)
{
if(!is_array($field)) $field = array($field);
usort($data, function($a, $b) use($field) {
$retval = 0;
foreach($field as $fieldname) {
if($retval == 0) $retval = strnatcmp($a[$fieldname],$b[$fieldname]);
}
return $retval;
});
return $data;
}
它工作得很好,但我想知道我如何改变它,以便传递第三个参数,排序方向(ASC或DESC)。
谢谢!
在你的代码中添加两个可以修复这个问题:
function sortArray($data, $field, $dir = "asc")
{
//All your sorting code
//Then:
return strtolower($dir) == "asc" ? $data: array_reverse($data);
}
这只是将数组反转,并在传递给第三个非"asc"的参数时返回数组。strtolower()允许你接受任何大小写("asc", "asc", "asc"等),所以你不必记住,它默认为asc,这是人们所期望的。
我认为你可以为你的排序函数创建一个包装器:
asc_sorter = function(a, b) {
return arraySorter(a, b);
}
desc_sorter = function(a, b) {
return -arraySorter(a, b);
}
然后调用asc_或desc_ sorter
您可以接受一个可选的布尔值以降序排序,并将其默认为false
。如果降序为true
,则只需将retval
乘以-1
:
function sortArray($data, $field, $descending = false)
{
if(!is_array($field)) $field = array($field);
usort($data, function($a, $b) use($field) {
$retval = 0;
foreach($field as $fieldname) {
if($retval == 0) $retval = strnatcmp($a[$fieldname],$b[$fieldname]);
}
return ($descending ? -1 : 1)*$retval;
});
return $data;
}
可以根据方向参数反转数组,如下所示:
function sortArray($data, $field, $direction)
/* sorting code */
if($direction == 'DESC')
return array_reverse($sorted_array);
else
return $sorted_array;
}