如何在 PHP 中解析 JSON 数组并显示在 HTML 表中？

Question

我需要在 PHP 中解析 JSON 数组响应并在 HTML 表中回显这些值。我对 PHP-JSON 很陌生，我无法找到这样做的方法。

$curl_response = curl_exec($curl);
echo $curl_response . PHP_EOL;

JSON 数组响应：

{
    "employees": [
        {
            "emp_id":101,
            "name":"Christ Joseph",
            "email":"emp101@example.com",
            "attendance": [
                {
                    "last_day_present":"13-05-2021",
                    "days_present":0,
                    "grade":A
                }
            ]
        },
        {
            "emp_id":102,
            "name":"Paolo Jobh",
            "email":"emp102@example.com",
            "attendance": [
                {
                    "last_day_present":"13-05-2021",
                    "days_present":100,
                    "grade":B
                }
            ]
        },
        {
            "emp_id":103,
            "name":"Subo Paul",
            "email":"emp103@example.com",
            "attendance": [
                {
                    "last_day_present":"13-05-2021",
                    "days_present":15,
                    "grade":B
                }
            ]
        },
    ]
}

PHP 脚本：

$json = json_decode($curl_response, true);

echo "<table border='1' width='50%' align='center'>";
foreach($json['employees'] as $data)
{
   if($json['employees'][0]['attendance']['days_present'] == 0) {
     //exclude the employees whose days_present is 0
   } else { 
   echo "<tr>";
   echo "<td>$json['employees']['emp_id']</td>";
   echo "<td>$json['employees']['email']</td>";
   echo "<td>$json['employees']['days_present']</td>";
   echo "<td>$json['employees'][0]['attendace']['grade']</td>";
   echo "</tr>";
  }
}

获取输出：

(empty table)

预期输出：

<table border="1" width="50%" align="center">
<!-- Display the JSON array response here -->
<tr>
  <td>102</td>
  <td>emp102@example.com</td>
  <td>100</td>
  <td>B</td>
</tr>
<tr>
  <td>103</td>
  <td>emp103@example.com</td>
  <td>15</td>
  <td>B</td>
</tr>

有人，请帮我弄清楚脚本有什么问题。有没有更好的方法可以更快地执行脚本并减少流量负载？

Answer 1

您正在使用的foreach/as 循环将$json['employees'] 数组的每个元素放入一个名为$data 的变量中。您需要像这样调整代码。

改变

foreach($json['employees'] as $data)
{
   if($json['employees'][0]['attendance']['days_present'] == 0) {
     //exclude the employees whose days_present is 0
   } else { 
   echo "<tr>";
   echo "<td>$json['employees']['emp_id']</td>";
   echo "<td>$json['employees']['email']</td>";
   echo "<td>$json['employees']['days_present']</td>";
   echo "<td>$json['employees'][0]['attendace']['grade']</td>";
   echo "</tr>";
  }
}

到

foreach($json['employees'] as $data)
{
   if($data['attendance'][0]['days_present'] == 0) {
     //exclude the employees whose days_present is 0
   } else { 
   echo "<tr>";
   echo "<td>" . $data['emp_id'] . "</td>";
   echo "<td>" . $data['email'] . "</td>";
   echo "<td>" . $data['attendance'][0]['days_present'] . "</td>";
   echo "<td>" . $data['attendance'][0]['grade'] . "</td>";
   echo "</tr>";
  }
}

Answer 2

很简单的问题；我重写了您提供的整个 json 数组并将其编码为 JSON，以查看应该如下所示的正确结构：

{
    "employees": [
        {
            "emp_id": 101,
            "name": "Christ Joseph",
            "email": "emp101@example.com",
            "attendance": {
                "last_day_present": "13-05-2021",
                "days_present": 0,
                "grade": "A"
            }
        },
        {
            "emp_id": 102,
            "name": "Paolo Jobh",
            "email": "emp102@example.com",
            "attendance": {
                "last_day_present": "13-05-2021",
                "days_present": 100,
                "grade": "B"
            }
        },
        {
            "emp_id": 103,
            "name": "Subo Paul",
            "email": "emp103@example.com",
            "attendance": {
                "last_day_present": "13-05-2021",
                "days_present": 15,
                "grade": "B"
            }
        }
    ]
}

1st：您的["attendance"]["grade"] 值周围没有引号。任何包含非字母数字字符或字母字符的内容都需要引号。只有数字值可以不加引号（如果我错了，请纠正我，但我很确定这是怎么回事）

第二个：在["attendance"] 值周围有方括号，这将它放在一个未命名的维度中，这实际上是不必要的，只会使检索它有点困难。

3rd： 底部最后一个逗号如下所示：}, 是您没有收到json_decode 任何回复的另一个原因。删除最后一个无意义的逗号并至少执行第一步，它应该可以工作。

这是一个 您的 JSON 数组，其中指出了错误：

{
        "employees": [
            {
                "emp_id":101,
                "name":"Christ Joseph",
                "email":"emp101@example.com",
                "attendance": [ # <---------- 2nd Problem 
                    {
                        "last_day_present":"13-05-2021",
                        "days_present":0,
                        "grade":A # <---------- 1st Problem
                    }
                ] # <---------- 2nd Problem
            },
            {
                "emp_id":102,
                "name":"Paolo Jobh",
                "email":"emp102@example.com",
                "attendance": [ # <---------- 2nd Problem
                    {
                        "last_day_present":"13-05-2021",
                        "days_present":100,
                        "grade":B # <---------- 1st Problem
                    }
                ] # <---------- 2nd Problem
            },
            {
                "emp_id":103,
                "name":"Subo Paul",
                "email":"emp103@example.com",
                "attendance": [ # <---------- 2nd Problem
                    {
                        "last_day_present":"13-05-2021",
                        "days_present":15,
                        "grade":B # <---------- 1st Problem
                    }
                ] # <---------- 2nd Problem
            }, # <---------- 3rd Problem
        ]
    }

所以基本上，你的 curl 响应是无效的。我不确定这是否是您可以控制的，但这看起来像是问题所在。 我把你的整个 JSON 数组放到了 sandbox.onlinephpfunctions.com 中，试图将它解码成一个数组并打印出来 (ref.)，但是直到我做了上面解释的几件事，它才能工作。