计算json中相同元素的数量

Question

我在这段简单的代码中使用php解析json

    <?php
    $json = file_get_contents('list.json'); 
    $data = json_decode($json,true);
    $records=$data['records'];
    foreach($records as $record)
    {
       echo $record['number']." ".$record['opened_at'];
    }
    ?>

但是我想回复一下我的json文件中有多少'number'元素如下所示

{
"records":[
  {
     "number":"INC018****",
  },
  {
     "number":"INC018****",
  },
  {
     "number":"INC018****",
  },
  {
     "number":"INC018****",   
  },

Answer 1

<?php
$json = file_get_contents('list.json'); 
$data = json_decode($json,true);
$records=$data['records'];
$numberCount = 0;
foreach($records as $record)
{
   $numberCount += isset($record['number']); // Here we go
   echo $record['number']." ".$record['opened_at'];
}
echo $numberCount;
?>

Answer 2

此功能可能会有所帮助：http://www.php.net/manual/en/function.array-count-values.php

$counts = array_count_values($records);
$numberCount = $counts['number'];