php foreach.从数组中选择特定的值，并将其用作显示循环的参数 - php foreach. select specific value from array and use it as parameter for display loop

php foreach. select specific value from array and use it as parameter for display loop

我希望能够显示当前登录的作者的图书标题。我使用PHP session

<? foreach ($books as $book ): ?>
<? foreach ($book as $selbook => $author): ?>
    <option value="$selbook>"$author['author'] == $_SESSION["sess_username"] ? ' selected="selected"' : ''?>> $author?></option>
<li class="active"><a href=""><span class="pull-right"><input id="button" type="submit" name="submitr" value="Edit"></span><i class="icon-fire$
<? echo htmlspecialchars($book['Title'], ENT_QUOTES, 'UTF-8'); ?> <strong> - </strong><em>
<? echo htmlspecialchars($book['author'], ENT_QUOTES, 'UTF-8');?></em></a></li>
<? endforeach; ?>
<? endforeach; ?>

你开始的第二个foreach:

<?php foreach ($book as $selbook => $author) { ?>

并以此结尾:

<?php endforeach; ?>

是不正确的。使用:

<?php foreach ($book as $selbook => $author): ?>
    // some code
<?php endforeach; ?>

还有，为什么要用<?php ?短标记未启用?使用<?，编写速度更快，代码可读性更强。另外，当你想要回显一些变量时，使用php标签使用这个:

<?=$variable;?>

速度更快，可读性更强。

更新

试试这个:

<? foreach ($books as $book ): ?>
 <? foreach ($book as $selbook => $author): ?>
  <option value="<?=$selbook;?>" <? if($author['author'] == $_SESSION["sess_username"]): ?>selected="selected"<? endif; ?> ><?=$author;?></option>
  <li class="active"><a href=""><span class="pull-right"><input id="button" type="submit"  name="submitr" value="Edit"></span><i class="icon-fire$
  <? echo htmlspecialchars($book['Title'], ENT_QUOTES, 'UTF-8'); ?> <strong> - </strong><em>
  <? echo htmlspecialchars($book['author'], ENT_QUOTES, 'UTF-8');?></em></a></li>
 <? endforeach; ?>
<? endforeach; ?>