Question

突然开始为以下代码收到此错误：

<?php foreach (get_the_terms(get_the_ID(), 'loan-club') as $cat) : ?>
<img src="<?php echo z_taxonomy_image_url($cat->term_id); ?>" title="ON LOAN AT: <?php echo $cat->name; ?>" />
<?php endforeach; ?>

有时候，分类学＆＃39; loan-club＆＃39;是空的。这可能是问题吗？如果是这样，有人能指出我正确的代码吗？

Answer 1

在if之前添加foreach条件：

<?php
$loan_club = get_the_terms(get_the_ID(), 'loan-club');

if(is_array($loan_club)) {
    foreach ($loan_club as $cat) {
      ?>
        <img src="<?php echo z_taxonomy_image_url($cat->term_id); ?>" title="ON LOAN AT: <?php echo $cat->name; ?>" />
      <?php
    } 
}
?>

请查看文档中的get_the_terms（）函数：https://developer.wordpress.org/reference/functions/get_the_terms/

该函数也可能返回WP_Error或false。如果返回WP_Error或false，则会导致错误并且foreach循环中断。

Answer 2

<?php foreach ((array)get_the_terms(get_the_ID(), 'loan-club') as $cat) : ?>
<img src="<?php echo z_taxonomy_image_url($cat->term_id); ?>" title="ON LOAN AT: <?php echo $cat->name; ?>" />
<?php endforeach; ?>

Note: to all the people complaining about typecast, please note that the OP asked cleanest way to skip a foreach if array is empty (emphasis is mine). A value of true, false, numbers or strings is not considered empty.

为foreach（）提供的参数无效

2 个答案: