无法清除PHP中的空元素


Cannot get rid of empty elements in PHP

花了几个小时阅读、研究,却弄不明白,这是我的代码:

    <?php
        $userid = "";
        $accessToken = "";
        function fetchData($url){
             $ch = curl_init();
             curl_setopt($ch, CURLOPT_URL, $url);
             curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
             curl_setopt($ch, CURLOPT_TIMEOUT, 20);
             $result = curl_exec($ch);
             curl_close($ch); 
             return $result;
        }
        $result = fetchData("https://api.instagram.com/v1/users/{$userid}/media/recent/?access_token={$accessToken}&count=-1");
        $result = json_decode($result);
    ?>
<?php foreach ($result->data as $post):{
        if (stripos($post->caption->text,'egypt') !== false) {
        unset($post);
        $post = (str_split($post->caption->text)); 
        $post = (array_filter($post));
        }
    }
    ?>
<img src="<?= $post->images->low_resolution->url?>" />
<?= $post->caption->text ?>
<?php endforeach ?>

正如你所看到的,我正试图消除其中提到的"埃及"的回复,我通过使用unset成功地做到了这一点。然而,即使使用array_filter,我仍然会得到空元素。HTML看起来是这样的:埃及照片的<img src="" />(正如你所能想象的)。

这是我不理解的:

<?php foreach ($result->data as $post):
{
        if (stripos($post->caption->text,'egypt') !== false) {
        }
        else{
        unset($post);
        $posta = (str_split($post->caption->text)); 
        $posta = (array_filter($post));
        $posta = array_filter($posta, 'strlen' );
    }
}
?>    
<img src="<?= $post->images->low_resolution->url?>" /><br>
<?= $post->caption->text ?><br><br>
<?php endforeach ?>

给了我想要的结果(只有埃及的照片和描述),但它也给了我一个PHP错误:Warning: array_filter() expects parameter 1 to be array, null given' and警告:array_filter()希望参数1是array,null给定`array_filter不应该删除null值吗?我只想用任何东西来代替这些错误。

我建议将循环更改为以下内容:

只有在找不到"埃及"时才打印出来。

<?php foreach ($result->data as $post){
    if (stripos($post->caption->text,'egypt') === false) {
      $post = (str_split($post->caption->text));?> 
      <img src="<?= $post->images->low_resolution->url?>" />
      <?= $post->caption->text ?>
<?php
    }
    else{
       unset $post;
    }
?>

或者,您可以先在一个循环中清理数组,然后在另一个循环打印条目。这可能会使以后更容易添加额外的"筛选器"。

<?php
    //edit --- typos clean_aray = array(); 
    $clean_array = array();
    foreach ($result->data as $post){
      if (stripos($post->caption->text,'egypt') === false) {
        $clean_array[] = $post;
      }
    }
    foreach ($clean_array as $post){
      $post = (str_split($post->caption->text));?> 
      <img src="<?= $post->images->low_resolution->url?>" />
      <?= $post->caption->text ?>
<?php
    }
?>

您可以将array_filter与strlen这样的回调函数一起使用,这将删除NULL、空字符串和FALSE,我所说的FALSE是指明确地为FALSE而不是0

$result = array_filter( $array, 'strlen' );