if语句- PHP if - else堆栈看起来很复杂 - if statement - PHP If-Else Stack seems convoluted

我正在使用PHP布局导航菜单并根据URL显示内容。

我已经到达了IF-ELSE堆栈，它决定要显示什么内容(通过加载必要的类和/或方法)。但是一定有更好的方式来写这个…有什么建议吗?

breadcrumb::getCrumb()是一个静态方法，用于根据索引值(URI请求，按'/'分割，然后保存在数组中)从URL中检索元素。

…(ArrayHelp::recValueSearch(breadcrumb::getCrumb(2)， Config::getNavPrimary())根据包含Config类导航列表的数组检查URI元素。

breadcrumb::setEmptyCrumb(1， "home")运行一个方法，如果值不存在或无效(在nav列表数组中)

<?php
// set bread crumbs
BreadCrumbs::setCrumbs($_SERVER['REQUEST_URI']);
BreadCrumbs::setEmptyCrumb(1, "home");
BreadCrumbs::setEmptyCrumb(2, "all");

if (BreadCrumbs::getCrumb(1) == 'about') {
    echo 'This is the <b>About</b> Page';
}
else if (BreadCrumbs::getCrumb(1) == 'contact') {
    echo 'This is the <b>Contact</b> Page';
}
else if (BreadCrumbs::getCrumb(1) == 'search') {
    echo 'This is the <b>Search</b> Page';
}
else if (BreadCrumbs::getCrumb(1) == 'home') {
    if (BreadCrumbs::getCrumb(2) == 'all') {
        echo 'This is the <b>Home</b> Page';
    }
    else if (ArrayHelp::recValueSearch(BreadCrumbs::getCrumb(2), Config::getNavSecondary())) {
        echo 'This is the list page for category: <b>' . BreadCrumbs::getCrumb(1) . '</b> and the country filter is: <b>'. BreadCrumbs::getCrumb(2) . '</b>';
    }
    else {
        echo 'change filter value and go to the <b>home</b> page';
    }
}
else if (ArrayHelp::recValueSearch(BreadCrumbs::getCrumb(1), Config::getNavPrimary())) {
    if (BreadCrumbs::getCrumb(2) == 'all') {
        echo 'This is the list page for category: <b>' . BreadCrumbs::getCrumb(1) . '</b> and the country filter is <b>all countries</b>';
    }
    else if (ArrayHelp::recValueSearch(BreadCrumbs::getCrumb(2), Config::getNavSecondary())) {
        echo 'This is the list page for category: <b>' . BreadCrumbs::getCrumb(1) . '</b> and the country filter is: <b>'. BreadCrumbs::getCrumb(2) . '</b>';
    }
    else {
        echo 'change filter value to all and go to category: <b>' . BreadCrumbs::getCrumb(1) . '</b>';
    }
}
else {
    echo 'redirect page to home/all';
}
?>

编辑:更改为Switch语句如下，稍微好一点…

    <?php
    $array_helper = new ArrayHelp;
    $valid_primary = $array_helper->recValueReturn(BreadCrumbs::getCrumb(1), Config::getNavPrimary());
    $valid_secondary = $array_helper->recValueReturn(BreadCrumbs::getCrumb(2), Config::getNavSecondary());
    switch (BreadCrumbs::getCrumb(1)) {
        case 'about' :
        case 'contact' :
        case 'search' :
            echo 'This is the <b>' . BreadCrumbs::getCrumb(1) . '</b> Page';
            break;
        case 'home' :
            switch (BreadCrumbs::getCrumb(2)) {
                case 'all' :
                    echo 'This is the <b>Home</b> Page';
                    break;
                case ($valid_secondary[1]) : 
                    echo 'This is the list page for category: <b>' . BreadCrumbs::getCrumb(1) . '</b> and the country filter is: <b>'. BreadCrumbs::getCrumb(2) . '</b>';
                    break;
                default:
                    echo 'change filter value and go to the <b>' . BreadCrumbs::getCrumb(1) . '</b> page';
                    break;
            }
            break;
        case ($valid_primary[1]) :
            switch (BreadCrumbs::getCrumb(2)) {
                case ($valid_secondary[1]) : 
                    echo 'This is the list page for category: <b>' . BreadCrumbs::getCrumb(1) . '</b> and the country filter is: <b>'. BreadCrumbs::getCrumb(2) . '</b>';
                    break;
                default:
                    echo 'change filter value and go to the <b>' . BreadCrumbs::getCrumb(1) . '</b> page';
                    break;
            }
            break;
        default:
            echo 'redirect page to home/all';
            break;
    }
?>

是的，switch语句更简洁一些

switch(BreadCrumbs::getCrumb(1)) {
   case 'about':
     echo 'This is the <b>About</b> Page';
     break;  
   case 'contact':
     echo 'This is the <b>Contact</b> Page';
     break;
   case 'search':
     echo 'This is the <b>Search</b> Page';
     break;

   // ....
   default: 
     // Default behavior
      break;
}

下一步是将每个页面打印输出放置在自己的函数中，或者将html外部化到模板文件中。

如果您的示例代码显示了您的完整需求，则可以通过使用getCrumb返回的实际字符串来大大简化其中一些:

  $crumb = ucfirst(BreadCrumbs::getCrumb(1));
  switch($crumb){
     case 'home': case 'foobar': # etc, etc
        echo "This is the <b>$crumb</b> Page";
        break; # or add some extra logic
     default:
        # handle invalid crumbs here
        break;
  }

(ucfirst用于使字符串的第一个字符大写)