Question

我正在尝试使用Json_decode PHP解码json ...但是收到错误为NULL JSON文件：

{"elements":[
    {"courseType":"v2.ondemand",
    "id":"69Bku0KoEeWZtA4u62x6lQ",
    "slug":"gamification",
    "name":"Gamification"
    },
    {"courseType":"v2.ondemand",
    "id":"0HiU7Oe4EeWTAQ4yevf_oQ",
    "slug":"missing-data",
    "name":"Dealing With Missing Data"
    },
    {"courseType":"v2.ondemand",
    "id":"5zjIsJq-EeW_wArffOXkOw",
    "slug":"vital-signs",
    "name":"Vital Signs: Understanding What the Body Is Telling Us"
    },
    {"courseType":"v2.ondemand",
    "id":"v9CQdBkhEeWjrA6seF25aw",
    "slug":"modern-art-ideas",
    "name":"Modern Art & Ideas"
    },{"courseType":"v2.ondemand",
    "id":"QgmoVdT2EeSlhSIACx2EBw",
    "slug":"evolvinguniverse",
    "name":"The Evolving Universe"
    }

我只需要选择ID，名称和课程类型

<?php

    $strings = file_get_contents("https://api.coursera.org/api/courses.v1");

    $arrays = json_decode($strings,true);      

 ?>



<div class="table-responsive">
    <table class="table table-bordered table-striped" id="coursedata">
        <tr>
            <th>Course ID</th>
            <th>Course Name</th>
            <th>Course Type</th>
         </tr>             
         <tr>
          <td><?php  print_r($arrays['elements']['id']);?></td>
         </tr>               
        </table>
     </div>

Answer 1

您可以使用foreach loop [1]遍历结果并将它们打印在表格中：

<?php

    $strings = file_get_contents("https://api.coursera.org/api/courses.v1");

    $arrays = json_decode($strings,true);      
 ?>



<div class="table-responsive">
    <table class="table table-bordered table-striped" id="coursedata">
        <tr>
            <th>Course ID</th>
            <th>Course Name</th>
            <th>Course Type</th>
         </tr>             
<?php
    foreach($arrays['elements'] as $element) {
        echo '<tr>';

        echo '<td>' . $element['id'] . '</td>';
        echo '<td>' . $element['name'] . '</td>';
        echo '<td>' . $element['courseType'] . '</td>';

        echo '</tr>';
    }
?>
        </table>
     </div>

PS：您可能想看看heredoc [2]，用于输出带有PHP变量的HTML。

Answer 2

您需要使用数组索引号访问数组数据：

<?php

    $strings = file_get_contents("https://api.coursera.org/api/courses.v1");

    $arrays = json_decode($strings,true);      

 ?>



<div class="table-responsive">
    <table class="table table-bordered table-striped" id="coursedata">
        <tr>
            <th>Course ID</th>
            <th>Course Name</th>
            <th>Course Type</th>
         </tr>             


    <?php for($i=0; $i<count($arrays); $i++) { ?>
<tr>
  <td><?php  echo $arrays['elements'][$i]['id'];?></td>
  <td><?php  echo $arrays['elements'][$i]['name'];?></td>
  <td><?php  echo $arrays['elements'][$i]['courseType'];?></td>
 </tr>
<?php } ?> 


        </table>
     </div>

Answer 3

尝试使用此代码json_decode

<?php
$jsonStr = '{"elements":[{"courseType":"v2.ondemand","id":"69Bku0KoEeWZtA4u62x6lQ","slug":"gamification","name":"Gamification"},{"courseType":"v2.ondemand","id":"0HiU7Oe4EeWTAQ4yevf_oQ","slug":"missing-data","name":"Dealing With Missing Data"},{"courseType":"v2.ondemand","id":"5zjIsJq-EeW_wArffOXkOw","slug":"vital-signs","name":"Vital Signs: Understanding What the Body Is Telling Us"},{"courseType":"v2.ondemand","id":"v9CQdBkhEeWjrA6seF25aw","slug":"modern-art-ideas","name":"Modern Art & Ideas"},{"courseType":"v2.ondemand","id":"QgmoVdT2EeSlhSIACx2EBw","slug":"evolvinguniverse","name":"The Evolving Universe"}]}';
$array = json_decode($jsonStr,true);

?>
<div class="table-responsive">
    <table class="table table-bordered table-striped" id="coursedata" border='1'>
        <tr>
            <th>
                Course ID
            </th>
            <th>
                Course Name
            </th>
            <th>
                Course Type
            </th>
        </tr>
        <?php
           foreach($array['elements'] as $k=>$v){
        ?>
        <tr>
            <td><?php  echo $v['id'];?></td>
            <td><?php  echo $v['name'];?></td>
            <td><?php  echo $v['courseType'];?></td>
        </tr>
        <?php
            }
        ?>
    </table>
</div>

未定义索引：id NULL

3 个答案: