1.很多时候会遇到二维数组，转为一维数组的时候会很苦恼，尤其是刚刚接触PHP的phper。
如下：将$arr转化为一维数组
$arr = Array (
Array ( 'uuid' => 'aaaaa' ),
Array ( 'uuid' => 'bbbbb' ),
Array ( 'uuid' => 'ccccc' ),
Array ( 'uuid' => 'sssss' ),
Array ( 'uuid' => 'ddddd' ),
Array ( 'uuid' => 'eeeee' ),
Array ( 'uuid' => 'fffff' ),
Array ( 'uuid' => 'ggggg' )
);
两种方法：
1.foreach遍历
$arr2 = array();
foreach ($arr as $key => $value) {
foreach ($value as $k => $v) {
$arr2[$key]=$v;
}
}
var_dump($arr2);
//array (size=8) 0 => string 'aaaaa' (length=5) 1 => string 'bbbbb' (length=5) 2 => string 'ccccc' (length=5) 3 => string 'sssss' (length=5) 4 => string 'ddddd' (length=5) 5 => string 'eeeee' (length=5) 6 => string 'fffff' (length=5) 7 => string 'ggggg' (length=5)
2.用array_column()函数
$arr2 = array_column($arr,'uuid');
var_dump($arr2);
//array (size=8) 0 => string 'aaaaa' (length=5) 1 => string 'bbbbb' (length=5) 2 => string 'ccccc' (length=5) 3 => string 'sssss' (length=5) 4 => string 'ddddd' (length=5) 5 => string 'eeeee' (length=5) 6 => string 'fffff' (length=5) 7 => string 'ggggg' (length=5)
