在foreach字符串中添加css类 - Adding a css class in a foreach string

我有以下代码，它在wordpress模板中显示相关项目，但我想添加一个类，每隔一个项目都附加一个right的css类，我需要修改什么才能实现这一点？

  <?php $rel = $related->show(get_the_ID(), true);
   foreach ($rel as $r) :
   echo '<div class=related-item><a href='.get_permalink($r->ID).'>'.'<div class=page-related-title>'.$r->post_title.'</div>'.get_the_post_thumbnail($r->ID, array(50,50)).'</a></div>';
   endforeach;?>

虽然这与Wordpress有关，但我认为它更多地与通用PHP编码有关，所以在这里而不是在WPSE。

尝试这个

<?php $rel = $related->show(get_the_ID(), true);
 $count = 0;
foreach ($rel as $r) {
 $class= ($count%2 == 0)?"right":"";
 echo '<div class="related-item '.$class.'"><a href='.get_permalink($r->ID).'>'.'<div class=page-related-title>'.$r->post_title.'</div>'.get_the_post_thumbnail($r->ID, array(50,50)).'</a></div>';
$count++;
}?>

如果数组有排序索引，则可以使用模计算或逐位运算。如果数组基于非数字或非序列数字，则需要添加一个计数器。

$i & 1 // odd using bitwise
$i % 2 // odd modulo

所以你会得到以下内容：

$i = 0;
foreach ($rel as $r) { // note that I have used curly brackets. I think it is cleaner  more standard
    $i++;
    $classes = array('related-item');
    if ($i % 2 == 0) $classes[] = 'right';
    echo '<div class="'.implode(' ', $classes).'"><a href='.get_permalink($r->ID).'>'.'<div class=page-related-title>'.$r->post_title.'</div>'.get_the_post_thumbnail($r->ID, array(50,50)).'</a></div>';
}

或者使用位：

$i = 0;
foreach ($rel as $r) { // note that I have used curly brackets. I think it is cleaner  more standard
    $i++;
    $classes = array('related-item');
    if ($i & 2 == 0) $classes[] = 'right';
    echo '<div class="'.implode(' ', $classes).'"><a href='.get_permalink($r->ID).'>'.'<div class=page-related-title>'.$r->post_title.'</div>'.get_the_post_thumbnail($r->ID, array(50,50)).'</a></div>';
}

或者，如果$rel具有基于零的排序索引：

foreach ($rel as $index => $r) { // note that I have used curly brackets. I think it is cleaner  more standard
    $classes = array('related-item');
    if ($index & 2 == 1) $classes[] = 'right';
    echo '<div class="'.implode(' ', $classes).'"><a href='.get_permalink($r->ID).'>'.'<div class=page-related-title>'.$r->post_title.'</div>'.get_the_post_thumbnail($r->ID, array(50,50)).'</a></div>';
}

    <?php $rel = $related->show(get_the_ID(), true);
       $i = 0;
       foreach ($rel as $r) {
           echo '<div class=related-item' . ($i++ % 2 ? '' :  ' right') . '><a href='.get_permalink($r->ID).'>'.'<div class=page-related-title>'.$r->post_title.'</div>'.get_the_post_thumbnail($r->ID, array(50,50)).'</a></div>';
       }
    ?>

像这样的东西。我的建议是尽量使用花括号而不是foreach（）：endforeach；

你的意思是：


$i = 0;
    foreach ($rel as $r) :
        $class = (($i % 2) == 0) ? "your_class"  : "";
            echo '<div class="related-item $class"><a href='.get_permalink($r->ID).'>'.'<div class=page-related-title>'.$r->post_title.''.get_the_post_thumbnail($r->ID, array(50,50)).'</a></div>';
        $i++;
    endforeach;

<?php
 foreach($rel as $key => $r) {
   /* here we check if $key is even and assign class name or empty string to $class variable  */
   ($key%2) ? $class = 'your-class-name' : $class = '';
   /* and here we just add $class variable to 'class="related-items " part. */
   /* so if $key is odd then $class will be empt and your div will have only 'related-item' class, and if $key is even then $class will hold 'your-class-name' value and div will have two classes: related-item and your-class-name */
   echo '<div class="related-item '.$class.'"><a href='.get_permalink($r->ID).'>'.'<div class=page-related-title>'.$r->post_title.'</div>'.get_the_post_thumbnail($r->ID, array(50,50)).'</a></div>';
 }
?>