php 多维数组上的 json_encode() - 带有字符串键
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/16419689/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
json_encode() on a multidimensional array - with string keys
提问by Patrick
I am creating an very large multidimensional array using PHP. Each object contains Name, ID, ParentID and Children. Children is an array of more objects in the same format.
我正在使用 PHP 创建一个非常大的多维数组。每个对象包含名称、ID、ParentID 和 Children。Children 是具有相同格式的更多对象的数组。
It is critical I name the IDs of each object - this helps me put each object under the correct parent. (In the code below, I use 101, 102 etc.)
我命名每个对象的 ID 很重要 - 这有助于我将每个对象放在正确的父项下。（在下面的代码中，我使用 101、102 等）
However, the problem I am having is when I return the array in JSON using json_encode. Each 'Children' array is being printed as an object, not an array - as shown in the JSON code below.
但是，我遇到的问题是当我使用json_encode. 每个“Children”数组都被打印为一个对象，而不是一个数组——如下面的 JSON 代码所示。
As I read on another SO thread here, they "are made as objects because of the inclusion of string keys" - although they are numbers, they are still strings.
正如我在此处的另一个 SO 线程上阅读的那样，它们“由于包含字符串键而被制作为对象”-尽管它们是数字，但它们仍然是字符串。
{
"101": {
"ID": "101",
"ParentID": "0",
"Name": "Root One"
"Children": {
"102": {
"ID": "102",
"ParentID": "101",
"Name": "Child One"
},
"103": {
"ID": "103",
"ParentID": "101",
"Name": "Child Two",
"Children": {
"104": {
"ID": "104",
"ParentID": "103",
"Name": "Child Child One"
}
}
},
Does anyone know how to overcome this issue?
有谁知道如何克服这个问题？
Edit:The JSON should look like this (the square brackets are important!):
编辑：JSON 应该是这样的（方括号很重要！）：
[
{
"ID": "101",
"ParentID": "0",
"Name": "Root One",
"Children": [
{
"ID": "102",
"ParentID": "101",
"Name": "Child One",
"Children": [
采纳答案by Patrick
I have now got a working solution which is fast and works well.
我现在有了一个快速且运行良好的工作解决方案。
Firstly, as written in SO link from the question;
In JSON, arrays only have numeric keys, whereas objects have string properties. The inclusion of a array key forces the entire outer structure to be an object by necessity.
In JSON; Curly braces hold objects (
{}), Square brackets hold arrays ([]).So using a string as a key will result in the
json_encodefunction returning objects, whereas reseting the keys will ensure it creates arrays.Therefore, just before I return my JSON encoded string, I run a function to reset all the array keys. The code I found on this SO thread (Reset array keys in multidimensional array)was particularly useful!
首先，正如问题中的 SO 链接所写的那样；
在 JSON 中，数组只有数字键，而对象具有字符串属性。包含数组键迫使整个外部结构必须成为一个对象。
在 JSON 中；花括号保存对象 (
{})，方括号保存数组 ([])。因此，使用字符串作为键将导致
json_encode函数返回对象，而重置键将确保它创建数组。因此，就在我返回 JSON 编码的字符串之前，我运行了一个函数来重置所有数组键。我在这个 SO 线程上找到的代码（在多维数组中重置数组键）特别有用！
回答by deceze
A JSON array has no explicit indexes, it's just an ordered list. The only JSON data structure that has named keysis an object. The literal should make this quite obvious:
JSON 数组没有明确的索引，它只是一个有序列表。唯一具有命名键的JSON 数据结构是对象。文字应该使这一点非常明显：
["foo", "bar", "baz"]
This arrayhas no named indices and there isn't any provision to add any.
这个数组没有命名索引，也没有任何添加的规定。
PHP conflates both lists and key-value stores into one arraydata type. JSON doesn't.
PHP 将列表和键值存储合并为一种array数据类型。JSON 没有。
回答by Eugen Mihailescu
This is your object:
这是你的对象：
$parent=new StdClass();
$parent->ID=101;
$parent->ParentID=0;
$parent->Name='Root One';
$child1=new StdClass();
$child1->ID=1011;
$child1->ParentID=$parent->ID;
$child1->Name='Child One';
$parent->Children[]=$child1;
$child1_1=new StdClass();
$child1_1->ID=10111;
$child1_1->ParentID=$child1->ID;
$child1_1->Name='Child One One';
$child1->Children[]=$child1_1;
This is your JSON convert function:
这是您的 JSON 转换函数：
echo json_encode($parent,JSON_PRETTY_PRINT);
and this is your object coded into JSON format:
这是您编码为 JSON 格式的对象：
{
"ID": 101,
"ParentID": 0,
"Name": "Root One",
"Children": [
{
"ID": 1011,
"ParentID": 101,
"Name": "Child One",
"Children": [
{
"ID": 10111,
"ParentID": 1011,
"Name": "Child One One"
}
]
}
]
}
The answer came later because I started learning PHP later. Anyway, some day, someone might find it useful.
后来得到了答案，因为我是后来开始学习 PHP 的。无论如何，总有一天，有人可能会发现它很有用。
回答by Damien Overeem
http://php.net/manual/en/function.json-decode.php
http://php.net/manual/en/function.json-decode.php
Set 2nd parameter of json_decode to true to atleast get assoc arrays.
将 json_decode 的第二个参数设置为 true 以至少获取关联数组。
Aside from that: javascript can't handle non-sequential/non-contiguous array indexes, so as soon as the id's are not sequential, json has no other option then to convert it into "string" indexes.
除此之外：javascript 无法处理非连续/非连续数组索引，因此只要 id 不是连续的，json 就没有其他选择，然后将其转换为“字符串”索引。
