使用多个条件对php中的关联数组进行排序
问题描述:
考虑以下数组
$details = array(
array('lname'=>'A', 'fname'=>'P','membkey'=>700,'head'=>'y'),
array('lname'=>'B', 'fname'=>'Q','membkey'=>540,'head'=>'n'),
array('lname'=>'C', 'fname'=>'R','membkey'=>700,'head'=>'n'),
array('lname'=>'D', 'fname'=>'S','membkey'=>540,'head'=>'y'),
array('lname'=>'E', 'fname'=>'T','membkey'=>700,'head'=>'n')
);
这里我想用 head 和 membkey 进行排序.同一个 membkey 元素的顶部元素应该有 'head=y' 并回显为,
Here I would like to sort with head and membkey. Top element of same membkey element should have 'head=y' and echoed as,
$details = array(
array('lname'=>'A', 'fname'=>'P','membkey'=>700,'head'=>'y'),
array('lname'=>'E', 'fname'=>'T','membkey'=>700,'head'=>'n'),
array('lname'=>'C', 'fname'=>'R','membkey'=>700,'head'=>'n'),
array('lname'=>'D', 'fname'=>'S','membkey'=>540,'head'=>'y'),
array('lname'=>'B', 'fname'=>'Q','membkey'=>540,'head'=>'n')
);
我试过如下
function orderbymemberKey( $a, $b ){
if ( $a[membkey] == $b[membkey] )
return 0;
return($a[membkey] < $b[membkey] )? -1 :1;
}
usort( $details, orderbymemberKey );
and it successfully order by membkey.
请提出任何建议.
答
您已经成功了一半(尽管您根据您的示例对 membkey
进行了倒序排序):
You're half way there (though you were sorting backwards for membkey
based on your example):
function order_by_member_key($a, $b)
{
if ($a['membkey'] == $b['membkey'])
{
// membkey is the same, sort by head
if ($a['head'] == $b['head']) return 0;
return $a['head'] == 'y' ? -1 : 1;
}
// sort the higher membkey first:
return $a['membkey'] < $b['membkey'] ? 1 : -1;
}
usort($details, "order_by_member_key");