结束（）期望参数1是数组，空给出

Question

好吧，所以我相当新的PHP，JSON等。我得到了一个任务，将HTML5表单输入到JSON数据库中，并且还记得那些信息。

<?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应该是自动递增，但是当我尝试，我得到这个错误：

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

是指这部分

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

Answer 1

替换此行：

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

与：

$data = json_decode($file, true); 

并且没有n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，你是不是保存在正确的json的一维数组中的数据，你居然让2D如果你使用$data[] = array(....) 如果你想保留它然后更换：

$last_item = end($data); 

有：

$last_item = end($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 
     ); 

取决于你如何想。 我希望它能帮助

Answer 2

如果你wan t获得数组的最后一个值，因为这是一个json数据，你必须首先使用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，但它仍然是一个数组下只是一个指标，获取指数和尝试这个办法：

$new_data = json_decode($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 
);