通过 PHP 修剪一个 json 数组答案

【问题标题】：Trim An json Array via PHP通过 PHP 修剪一个 json 数组
【发布时间】：2017-02-16 08:23:08
【问题描述】：

如何修剪这个数组？我想回显我数组的第一个对象，即id，我的意思是id的3行

 <?php
    $con=mysqli_connect("localhost","root","","arrayy");
    // Check connection
    if (mysqli_connect_errno())
      {
      echo "Failed to connect to MySQL: " . mysqli_connect_error();
      }
 $sql="SELECT `survey_answers` FROM `user_survey_start`";

if ($result=mysqli_query($con,$sql)){

 while ($row = mysqli_fetch_row($result)){

    $json = $row[0];
    $jason_array  = json_decode($json,true);
    foreach ($jason_array as $data){
        $id[] = $data['id'];
        //$answer[] = $data['answer'];
      // $type[] = $data['type'];

        // here code to insert/update values to db column
    }

    echo implode(',',$id)."</br>";
   // echo implode(',',$answer);
  //  echo implode (',',$type);
  }

}
mysqli_close($con);
?>

请看一下这张照片中的输出

【问题讨论】：

print_r($id) 和有问题的推杆
不正确，给我Array ( [0] => 26 [1] => 30 [2] => 31 [3] => 32 [4] => 33 ) Array ( [0] => 26 [1] => 30 [2] => 31 [3] => 32 [4] => 33 [5] => 40 [6] => 30 [7] => 31 [8] => 32 [9] => 33 ) Array ( [0] => 26 [1] => 30 [2] => 31 [3] => 32 [4] => 33 [5] => 40 [6] => 30 [7] => 31 [8] => 32 [9] => 33 [10] => 100 [11] => 200 [12] => 300 [13] => 400 )
implode() 是错误的使用方式。

标签： php arrays json object

【解决方案1】：

你需要重新初始化 $id 数组。试试这个

<?php
    $con=mysqli_connect("localhost","root","","arrayy");
    // Check connection
    if (mysqli_connect_errno())
      {
      echo "Failed to connect to MySQL: " . mysqli_connect_error();
      }
 $sql="SELECT `survey_answers` FROM `user_survey_start`";

if ($result=mysqli_query($con,$sql)){

 while ($row = mysqli_fetch_row($result)){

    $json = $row[0];
    $jason_array  = json_decode($json,true);
    $id = array();
    foreach ($jason_array as $data){
        $id[] = $data['id'];
        //$answer[] = $data['answer'];
      // $type[] = $data['type'];

        // here code to insert/update values to db column
    }

    echo implode(',',$id)."</br>";
   // echo implode(',',$answer);
  //  echo implode (',',$type);
  }

}
mysqli_close($con);
?>

【讨论】：

这里有什么变化？
Yessssssss，感谢它。