Php 如何正确地将if语句放入另一个字符串中

我是学习php的新手，我正在为自己开发一个电子商务网站

我几乎能理解代码，但似乎无法正确理解此语法。我基本上想要实现的是，如果是列表中的子类别，则在

标记中插入一个类

为我缺乏知识道歉，如果有人能帮我纠正这一点，我将非常感谢

所以原始代码是

$categories_string .= '<li><a href="';

我想显示完整的php文件会很有帮助，粘贴在下面我用/*******标记了我要编辑的行这是我要编辑的行********/：

<?php

class bm_categories {

var $code = 'bm_categories';

var $group = 'boxes';

var $title;

var $description;

var $sort_order;

var $enabled = false;



function bm_categories() {

  $this->title = MODULE_BOXES_CATEGORIES_TITLE;

  $this->description = MODULE_BOXES_CATEGORIES_DESCRIPTION;



  if ( defined('MODULE_BOXES_CATEGORIES_STATUS') ) {

    $this->sort_order = MODULE_BOXES_CATEGORIES_SORT_ORDER;

    $this->enabled = (MODULE_BOXES_CATEGORIES_STATUS == 'True');



    $this->group = ((MODULE_BOXES_CATEGORIES_CONTENT_PLACEMENT == 'Left Column') ? 'boxes_column_left' : 'boxes_column_right');

  }

}



function tep_show_category($counter) {

  global $tree, $categories_string, $cPath_array;

  for ($i=0; $i<$tree[$counter]['level']; $i++) {

    //$categories_string .= "&nbsp;&nbsp;";

  }

 /******THIS IS THE LINE I AM TRYING EDIT********/ $categories_string .= '<li><a href="';


  if ($tree[$counter]['parent'] == 0) {

    $cPath_new = 'cPath=' . $counter;

  } else {

    $cPath_new = 'cPath=' . $tree[$counter]['path'];

  }

  $categories_string .= tep_href_link(FILENAME_DEFAULT, $cPath_new) . '">';



  if (isset($cPath_array) && in_array($counter, $cPath_array)) {

    $categories_string .= '<strong>';

  }


 // display category name

  $categories_string .= $tree[$counter]['name'];



  if (isset($cPath_array) && in_array($counter, $cPath_array)) {

    $categories_string .= '</strong>';

  }



  if (tep_has_category_subcategories($counter)) {

    $categories_string .= '';

  }

    if (SHOW_COUNTS == 'true') {

    $products_in_category = tep_count_products_in_category($counter);

    if ($products_in_category > 0) {

      $categories_string .= '<span class="mj-countcolor">&nbsp;(' . $products_in_category . ')</span>';

    }

  }

  $categories_string .= '</a></li>';





  if ($tree[$counter]['next_id'] != false) {

    $this->tep_show_category($tree[$counter]['next_id']);

  }

}



function getData() {

  global $categories_string, $tree, $languages_id, $cPath, $cPath_array;



  $categories_string = '';

  $tree = array();



  $categories_query = tep_db_query("select c.categories_id, cd.categories_name, c.parent_id from " . TABLE_CATEGORIES . " c, " . TABLE_CATEGORIES_DESCRIPTION . " cd where c.parent_id = '0' and c.categories_id = cd.categories_id and cd.language_id='" . (int)$languages_id ."' order by sort_order, cd.categories_name");

  while ($categories = tep_db_fetch_array($categories_query))  {

    $tree[$categories['categories_id']] = array('name' => $categories['categories_name'],

                                                'parent' => $categories['parent_id'],

                                                'level' => 0,

                                                'path' => $categories['categories_id'],

                                                'next_id' => false);



    if (isset($parent_id)) {

      $tree[$parent_id]['next_id'] = $categories['categories_id'];

    }



    $parent_id = $categories['categories_id'];



    if (!isset($first_element)) {

      $first_element = $categories['categories_id'];

    }

  }



  if (tep_not_null($cPath)) {

    $new_path = '';

    reset($cPath_array);

    while (list($key, $value) = each($cPath_array)) {

      unset($parent_id);

      unset($first_id);

      $categories_query = tep_db_query("select c.categories_id, cd.categories_name, c.parent_id from " . TABLE_CATEGORIES . " c, " . TABLE_CATEGORIES_DESCRIPTION . " cd where c.parent_id = '" . (int)$value . "' and c.categories_id = cd.categories_id and cd.language_id='" . (int)$languages_id ."' order by sort_order, cd.categories_name");

      if (tep_db_num_rows($categories_query)) {

        $new_path .= $value;

        while ($row = tep_db_fetch_array($categories_query)) {

          $tree[$row['categories_id']] = array('name' => $row['categories_name'],

                                               'parent' => $row['parent_id'],

                                               'level' => $key+1,

                                               'path' => $new_path . '_' . $row['categories_id'],

                                               'next_id' => false);



          if (isset($parent_id)) {

            $tree[$parent_id]['next_id'] = $row['categories_id'];

          }



          $parent_id = $row['categories_id'];



          if (!isset($first_id)) {

            $first_id = $row['categories_id'];

          }



          $last_id = $row['categories_id'];

        }

        $tree[$last_id]['next_id'] = $tree[$value]['next_id'];

        $tree[$value]['next_id'] = $first_id;

        $new_path .= '_';

      } else {

        break;

      }

    }

  }



  $this->tep_show_category($first_element);



  $data = '<div class="ui-widget infoBoxContainer mj-categoriessidebox">' .

          '  <div class="ui-widget-header infoBoxHeading">' . MODULE_BOXES_CATEGORIES_BOX_TITLE . '</div>' .

          '  <div class="ui-widget-content infoBoxContents"><ul>
          <li><a href="/products_new.php">What\'s New?</a></li>
          <li><a href="/specials.php">Specials</a></li>


          '. $categories_string .'</ul></div>' .

          '</div>';



  return $data;

}



function execute() {

  global $SID, $oscTemplate;



  if ((USE_CACHE == 'true') && empty($SID)) {

    $output = tep_cache_categories_box();

  } else {

    $output = $this->getData();

  }



  $oscTemplate->addBlock($output, $this->group);

}



function isEnabled() {

  return $this->enabled;

}



function check() {

  return defined('MODULE_BOXES_CATEGORIES_STATUS');

}



function install() {

  tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function, date_added) values ('Enable Categories Module', 'MODULE_BOXES_CATEGORIES_STATUS', 'True', 'Do you want to add the module to your shop?', '6', '1', 'tep_cfg_select_option(array(\'True\', \'False\'), ', now())");

  tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function, date_added) values ('Content Placement', 'MODULE_BOXES_CATEGORIES_CONTENT_PLACEMENT', 'Left Column', 'Should the module be loaded in the left or right column?', '6', '1', 'tep_cfg_select_option(array(\'Left Column\', \'Right Column\'), ', now())");

  tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, date_added) values ('Sort Order', 'MODULE_BOXES_CATEGORIES_SORT_ORDER', '0', 'Sort order of display. Lowest is displayed first.', '6', '0', now())");

}



function remove() {

  tep_db_query("delete from " . TABLE_CONFIGURATION . " where configuration_key in ('" . implode("', '", $this->keys()) . "')");

}



function keys() {

  return array('MODULE_BOXES_CATEGORIES_STATUS', 'MODULE_BOXES_CATEGORIES_CONTENT_PLACEMENT', 'MODULE_BOXES_CATEGORIES_SORT_ORDER');

    }

  }

?>

---

或者，在这种情况下，您也可以使用三元运算符：

$categories_string .= '<li class="'.(tep_has_category_subcategories() ? 'hello_class' : '').'"><a href="';

---

最后，我找到了一个办法，将CLA添加到子类别中

$categories_string .= '<li class="';

if ($tree[$counter]['level'] == 1) {
$categories_string .= 'sub';
}

$categories_string .= '"><a href="';

正如@Ghost所指出的，更短的代码应该是

$categories_string .= '<li class="' . ($tree[$counter]['level'] == 1 ? 'sub' : '') . '"><a href="';

---

谢谢你的快速回答。第一个示例使列表中的每个项目都具有类，而不管它是否为子类别我想这是我的错，也许我用了错误的片段。您的第二个示例使列表中断。但是，我现在可以更好地看到语法了。感谢您的帮助，我现在已将完整文件粘贴到上面-有什么想法可以实现我要做的吗？使列表中的每个项目都具有类，而不管它是否为子类别。\u我想这是我的错，也许我用了错误的片段。很好的简短代码：我现在已经粘贴了上面的完整文件-有什么想法可以实现我想要做的吗？@BillOfUK如果你看到了你打算放它的部分，我不明白，那真的是你想要做的吗？如果函数tep_有_category_子类别返回true，则要连接空字符串？=；？而不是空字符串。。。我将输入一个类的名称，例如：“sub”-我希望所有子类别都有class='sub'@BillOfUK哇，很高兴你做了一个解决方案，而不是强制使用该函数lol。然后你可以应用三元$categories\u字符串。='

$categories_string .= '<li class="';

if (tep_has_category_subcategories()) {
    $categories_string .= '';
}

$categories_string .= '"><a href="';

if (tep_has_category_subcategories()) {
    $class = 'xyz';
}
else {
    $class = '';
}

$categories_string .= "<li class='$class'><a href='";

$categories_string .= '<li class="'.(tep_has_category_subcategories() ? 'hello_class' : '').'"><a href="';

$class = '';
if(tep_has_category_subcategories()) {
    $class = 'sub';
}

$categories_string .= "<li class='$class'><a href='";

(tep_has_category_subcategories() ? 'hello_class' : '')
   ^ if this function is true         do this  /else ^ do this

$categories_string .= '<li class="';

if ($tree[$counter]['level'] == 1) {
$categories_string .= 'sub';
}

$categories_string .= '"><a href="';

$categories_string .= '<li class="' . ($tree[$counter]['level'] == 1 ? 'sub' : '') . '"><a href="';