php数组插入到指定位置？

Question

$arr = array(
    'tt' => 1333,
    'cc' => 333,
    'aaz' => 2333,
    'ee' => 78,
)

/*
 插入一个【 键 'bb' 值 123】到tt后边得 $arr
Array
(
    [tt] => 1333
    [bb] => 123
    [cc] => 333
    [aaz] => 2333
    [ee] => 78
)
*/

Answer 1

$bb=123;
$tt=$arr['tt'];
$temp_arr=compact('tt','bb');
$new_arr=array_merge($temp_arr,$arr);

Answer 2

array_splice($array,要插入的位置,0,要插入的数组)

Answer 3

用自带的array_splice无法自定义键值，只能默认用数字索引，用下面的方法简单封装可以实现你的要求

        function array_insert (&$array, $position, $insert_array) {
            $first_array = array_splice ($array, 0, $position);
            $array = array_merge ($first_array, $insert_array, $array);
        }


        $arr = array(
            'tt' => 1333,
            'cc' => 333,
            'aaz' => 2333,
            'ee' => 78,
        );
        $temp["bb"] = 33;
        array_insert($arr,1,$temp);
        var_dump($arr);