我正在使用高级自定义字段，并试图构建一个导航菜单，其中当前项目有一个额外的类，让他们知道自己在哪里。

The entire structure in question. It\'s using ACF repeater fields:

<?php if(get_field(\'main_nav\', 53)): ?>
<?php while(has_sub_field(\'main_nav\', 53)): ?>
<li><a 

<?php 

$link1 = the_permalink();
$link2 = the_sub_field(\'link_url\');

if ( $link1 == $link2 ) {?> class="s4-secondary-nav-current" <?php } ?> 

href="<?php the_sub_field(\'link_url\'); ?>"><?php the_sub_field(\'link_text\'); ?></a></li>

<?php endwhile; ?>
<?php endif; ?>

Specific conditional:

<?php 

$link1 = the_permalink();
$link2 = the_sub_field(\'link_url\');

if ( $link1 == $link2 ) { echo \'class="s4-secondary-nav-current"\'; } else {} ?>

似乎发生的是$link1和$link2只是在HTML中打印出来的。

Was also trying to do something like this that gets same results as above:

<?php if ( the_permalink() == the_sub_field(\'link_url\') ) {?> class="s4-secondary-nav-current" <?php } ?> 

$link1 = get_permalink();
$link2 = get_sub_field(\'link_url\');

if ( the_permalink() == \'test\' ) {

echo get_the_permalink();
if ( \'\' == \'test\' ) {