Question

好吧，所以我对PHP，JSON等都很新。我得到了一个将HTML5表单输入到JSON数据库中的任务，并且还要记住该信息。

<?php
$f_name     = $_POST['f_name'];
$l_name     = $_POST['l_name'];
$u_email    = $_POST['u_email'];
$u_adress   = $_POST['u_adress'];
$u_postcode = $_POST['u_postcode'];
$u_place    = $_POST['u_place'];
$u_birth    = $_POST['u_birth'];

$file = file_get_contents("data.json");
$data = json_decode('data.json', true);

$last_item    = end($data);
$last_item_id = $last_item['id'];



$data[] = array(

    'f_name'=>$f_name,
    'l_name'=>$l_name,
    'u_email'=>$u_email,
    'u_adress' =>$u_adress,
    'u_postcode' =>$u_postcode,
    'u_place'=>$u_place,
    'u_birth'=>$u_birth,
    'id' =>++$last_item_id
    );


file_put_contents('data.json', json_encode($data));
?>

这是输出

[{"f_name":"Jack","l_name":"Smith","u_email":"jacksmith@hotmail.com","u_adress":"Something 1","u_postcode":"1111 AA","u_place":"SomeCity","u_birth":"jjjj-mm-dd","id":1}]

所以ID应该是自动增量但是当我尝试时我得到这个错误：

end() expects parameter 1 to be array, null given

指的是这部分

 $last_item    = end($data);
 $last_item_id = $last_item['id'];

Answer 1

如果你想得到这个是json数据的数组的最后一个值，你必须先使用json_decode。

$data = '[{"f_name":"Jack","l_name":"Smith","u_email":"jacksmith@hotmail.com","u_adress":"Something 1","u_postcode":"1111 AA","u_place":"SomeCity","u_birth":"jjjj-mm-dd","id":"1"}]';

因为当你解码它时，它仍然在一个数组下但只有一个索引，得到那个索引并试试这个：

$new_data = json_decode($data, true);
$last_item_id = end($new_data);
$id = $last_item_id = $last_item_id["id"];

$data = array(
'f_name'=>$f_name,
'l_name'=>$l_name,
'u_email'=>$u_email,
'u_adress' =>$u_adress,
'u_postcode' =>$u_postcode,
'u_place'=>$u_place,
'u_birth'=>$u_birth,
'id' => $id + 1
);

Answer 2

替换此行：

$data = json_decode('data.json', true);

使用：

$data = json_decode($file, true);

并且无需再次提取id。删除：

$last_item_id = $last_item['id'];

使用last_item后：

$data = array(

    'f_name'=>$f_name,
    'l_name'=>$l_name,
    'u_email'=>$u_email,
    'u_adress' =>$u_adress,
    'u_postcode' =>$u_postcode,
    'u_place'=>$u_place,
    'u_birth'=>$u_birth,
    'id' =>++$last_item
    );

请注意，如果您使用$data[] = array(....)，则不会将数据保存在正确的json 1D阵列中如果你想保留它，那么替换：

$last_item = end($data);

使用：

$last_item = end($data[0]);

长话短说，工作代码可以是：

$data = json_decode($file, true);
$last_item = end($data[0]);
 $data[] = array(

        'f_name'=>$f_name,
        'l_name'=>$l_name,
        'u_email'=>$u_email,
        'u_adress' =>$u_adress,
        'u_postcode' =>$u_postcode,
        'u_place'=>$u_place,
        'u_birth'=>$u_birth,
        'id' =>++$last_item
        );

OR

$data = json_decode($file, true);
$last_item = end($data);
 $data = array(

        'f_name'=>$f_name,
        'l_name'=>$l_name,
        'u_email'=>$u_email,
        'u_adress' =>$u_adress,
        'u_postcode' =>$u_postcode,
        'u_place'=>$u_place,
        'u_birth'=>$u_birth,
        'id' =>++$last_item
        );

取决于你想要的。 我希望它有所帮助

end（）期望参数1为数组，给定为null

2 个答案: