PHP一维数组与二维数组相互转换的示例

<?php
header("Content-Type:text/html; charset=utf-8");
$asr[1] = array("a","b","c","d");
$asr[2] = array("a","b","c","d");
$asr[3] = array("a","b","c","d");
$newarray = array();
foreach($asr as $a)
{
    $newarray[] = $a;
}
print_r($newarray);
?>

Array (
[0] => Array (
[0] => a
[1] => b
[2] => c
[3] => d )
[1] => Array (
[0] => a
[1] => b
[2] => c
[3] => d )
[2] => Array (
[0] => a
[1] => b
[2] => c
[3] => d )
)

<?php
header("Content-Type:text/html; charset=utf-8");
$msg = array(
  array(
    'id'=>'45',
    'name'=>'jack'
  ),
  array(
    'id'=>'34',
    'name'=>'mary'
  ),
  array(
    'id'=>'78',
    'name'=>'lili'
  ),
);
?>

foreach($msg as $k => $v){
        $ids[] = $id;
        $names[] = $name;
      }

$ids = array_column($msg, 'id');
$names = array_column($msg, 'name');

Array(
　　[0]=>jack
　　[1]=>mary
　　[2]=>lili
)

Array(
　　[45]=>jack
　　[34]=>mary
　　[78]=>lili
)