[英]How to build tree structure from array in PHP
我有下表:
$arr = array(
array('id'=>100, 'year'=>2019, 'month'=>9, 'name'=>'a'),
array('id'=>101, 'year'=>2019, 'month'=>12, 'name'=>'b'),
array('id'=>102, 'year'=>2020, 'month'=>1, 'name'=>'c'),
array('id'=>103, 'year'=>2020, 'month'=>2, 'name'=>'d'),
);
使用下面的代碼
$tree = array();
foreach ($arr as $row) {
$tree[$row['year']] = array(
$row['month'] => array (
'id' => $row['id'],
'name' => $row['name'],
),
);
}
我想得到以下結果 - 這個結構是一棵樹:
Array
(
[2019] => Array
(
[9] => Array
(
[id] => 100
[name] => a
)
[12] => Array
(
[id] => 101
[name] => b
)
)
[2020] => Array
(
[1] => Array
(
[id] => 102
[name] => c
)
[2] => Array
(
[id] => 103
[name] => d
)
)
)
不幸的是,我只得到一個帶有單個“分支”的關注:
Array
(
[2019] => Array
(
[12] => Array
(
[id] => 101
[name] => b
)
)
[2020] => Array
(
[2] => Array
(
[id] => 103
[name] => d
)
)
)
這里缺少什么? 為什么前面的行從結構中消失了?
由於您希望年份和月份作為主要索引,因此在將數據添加到$tree
時需要同時使用這兩個索引...
$tree = array();
foreach ($arr as $row) {
$tree[$row['year']][$row['month']] = [ 'id' => $row['id'],
'name' => $row['name']];
}
使用您的測試數據,這給出了...
Array
(
[2019] => Array
(
[9] => Array
(
[id] => 100
[name] => a
)
[12] => Array
(
[id] => 101
[name] => b
)
)
[2020] => Array
(
[1] => Array
(
[id] => 102
[name] => c
)
[2] => Array
(
[id] => 103
[name] => d
)
)
)
您的密鑰名稱有誤 - bl_year, bl_month
不存在:
foreach ($arr as $row) {
$tree[$row['year']] = array(
$row['month'] => array (
'id' => $row['id'],
'name' => $row['name'],
),
);
}
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.