这个三元运算符出了什么问题？

Question

我使用这样的分页系统:

<?php
$p = $_GET['p'];

switch($p)
{
    case "start":
        $p = "pages/start.php";
        $currentPageId = 1;
    break;

    case "customers":
        $p = "pages/customers.php";
        $currentPageId = 2;
    break;

    default:
        $p = "pages/start.php";
        $currentPageId = 1;
    break;
}
?>

我想将CSS设置class="active"为我所在页面的菜单项.

如果我打印这样的<li>项目它是有效的:

<li><a href="?p=start" <?php if ($currentPageId == 1) {echo "class='active'";}else {} ?>>Start</a></li>

但我想用三元运算符代替.我试过这段代码,但它不起作用:

<li><a href="?p=start" <?php ($currentPageId == '1') ? 'class="active"' : '' ?>>Startsida</a></li>

知道为什么吗？

编辑 所以问题是我错过了echo.现在让我稍微扩展一下这个问题......

我需要将我的整个内容封装<ul>在<?php ?>标签内.所以我想要的是这样的:

echo "<div id='nav'>";
 echo "<ul>";

   echo "<li><a href='?p=start' /* ternary operator to match if the page I'm on is equal to $currentPageId as defined in the paging system (above), if so set class='active' else do nothing*/>Start</a></li>;
   echo "<li><a href='?p=customers' /* ternary operator to match if the page I'm on is equal to $currentPageId as defined in the paging system (above), if so set class='active' else do nothing*/>Customers</a></li>;


 echo "</ul>";
echo "</div>";

我需要这样做,因为我将根据if语句显示链接.."如果用户是管理员显示此链接,否则不要"......任何人都有解决方案？

Answer 1

你错过了一个回声:

<li><a href="?p=start" <?php echo (($currentPageId == '1') ? 'class="active"' : '') ?>>Startsida</a></li>

这应该够了吧.

解决第二个问题:

<?php
if($something == true) {
    echo "<div id='nav'>"."\n<br>".
            "<ul>"."\n<br>".
                '<li><a href="?p=start"'. (($currentPageId == '1') ? 'class="active"' : '') .'>Startsida</a></li>'."\n<br>".
                '<li><a href="?p=customers" '. (($currentPageId == '1') ? 'class="active"' : '') .' >Customers</a></li>'."\n<br>".
            "</ul>"."\n<br>".
            "</div>"."\n<br>";
}
?>