获取JSON的第一个条目

Question

我在 URL 中有这个 JSON:

{"success":true,"rgInventory":{"6073259621":{"id":"6073259621","classid":"1660549198","instanceid":"188530139","amount":"1","pos":1}}}

我需要获取 rgInventory 之后的第一个条目。问题是问题是假设我不知道有"6073259621"。我不知道那里有什么如何获得它？

我尝试了这个但不起作用：

$obj = json_decode(file_get_contents($url), true);
$obj2 = json_decode(json_encode($obj['rgInventory']), true);
$obj3 = json_decode(json_encode($obj2), true); 
echo $obj3;

Answer 1

如果 JSON 字符串有效且如下所示

{ "success":true,
  "rgInventory":{
      "6073259621":{
          "id":"6073259621",
          "classid":"1660549198",
          "instanceid":"188530139",
          "amount":"1",
          "pos":1
       }
    }
}

get the decode in $obj like

  $obj = json_decode(file_get_contents($url), true);

then your first entry would be

 echo array_keys($obj['rgInventory'])[0];

to understand it clearly and to know where is "6073259621"

$obj = json_decode(file_get_contents($url), true);
var_dump($obj);

also note the difference

$json = '{"a":1,"b":2,"c":3,"d":4,"e":5}';

var_dump(json_decode($json));
var_dump(json_decode($json, true));

输出将是..

// decode as object
object(stdClass)#1 (5) {
    ["a"] => int(1)
    ["b"] => int(2)
    ["c"] => int(3)
    ["d"] => int(4)
    ["e"] => int(5)
}

// decode as array
array(5) {
    ["a"] => int(1)
    ["b"] => int(2)
    ["c"] => int(3)
    ["d"] => int(4)
    ["e"] => int(5)
}

Answer 2

在 JSON 解码后：

$obj = json_decode(file_get_contents($url), true);

您可以使用 reset.

从 rgInventory 中获取第一项，而不管它的键是什么。

$first_entry = reset($obj['rgInventory']);

Answer 3

这是使用 each() 获取键和值（数组）的简单方法：

$data = json_decode(file_get_contents($url), true);

list($key, $val) = each($data['rgInventory']);

echo $key;
print_r($val);

产量：

6073259621
Array
(
    [id] => 6073259621
    [classid] => 1660549198
    [instanceid] => 188530139
    [amount] => 1
    [pos] => 1
)

但我只是注意到 id 与密钥相同，所以并不需要。

获取JSON的第一个条目

Obtain the first entry of JSON

php

json

decode