我的目标是用 PHP 编写一个 foreach 循环,它可以在 中搜索具有最低
并查找一周内提供了多少次食物。例如,代码应按如下方式回显结果:id
值(即 5188)的食物 name
(即鸡肉锅派) >menu
1.鸡肉馅饼:3次
2.罗西尼巡回赛:1次
3.牛排:1次
4.酒馆三明治:0次
5.炸鱼薯条:2次
请注意,XML 数据如下所示:
<foods total="5">
<food>
<id>5188</id>
<yourfood>
<name>Chicken Pot Pie</name>
</yourfood>
</food>
<food>
<id>5189</id>
<yourfood>
<name>Tournedos Rossini</name>
</yourfood>
</food>
<food>
<id>5190</id>
<yourfood>
<name>Beefsteak</name>
</yourfood>
</food>
<food>
<id>5191</id>
<yourfood>
<name>Tavern Sandwich</name>
</yourfood>
</food>
<food>
<id>5192</id>
<yourfood>
<name>Fish&Chips</name>
</yourfood>
</food>
</foods>
<weekdays total="7">
<day>
<date>01-16-2016</date>
<menu>We have served Beefsteak for today.</menu>
</day>
<day>
<date>01-17-2016</date>
<menu>We have served Fish&Chips for today.</menu>
</day>
<day>
<date>01-18-2016</date>
<menu>Today, there is Chicken Pot Pie for you.</menu>
</day>
<day>
<date>01-19-2016</date>
<menu>Fish&Chips is one of the best foods in our restaurant</menu>
</day>
<day>
<date>01-20-2016</date>
<menu>Welcome home! Tournedos Rossini!</menu>
</day>
<day>
<date>01-21-2016</date>
<menu>Chicken Pot Pie</menu>
</day>
<day>
<date>01-22-2016</date>
<menu>Chicken Pot Pie is one of our most delicious dishes.</menu>
</day>
</weekdays>
最佳答案
幸运的是,最低的 ID 排在最前面,然后完全按顺序直到最高的 ID。这是按文档顺序排列的,SimpleXML XPath 是按文档顺序排列的,因此要拥有所有名称:
/*/food//name
接下来,您想要查看所有工作日菜单描述中该术语的使用频率。对于那些您需要从工作日 XML 文档中查看所有这些文本的人:
/*/day/menu
在 PHP 代码中,它很简单:
$foods = simplexml_load_string($foodsBuffer);
$weekdays = simplexml_load_string($weekdaysBuffer);
$names = $foods->xpath('/*/food//name');
$menus = $weekdays->xpath('/*/day/menu');
现在您关心的是查看每个名称:
foreach ($names as $i => $name) {
...
}
这可能就是您正在寻找的foreach
。然而它还没有完成,您需要检查 $name
出现在 $menus
条目中的频率。
这是文本比较,PCRE 库是 PHP 中一个适合文本且与 SimpleXML 中使用的 UTF-8 兼容的库。
它有一个名为 preg_grep
的方便函数,可以过滤数组中的匹配项:
$pattern = sprintf('/%s/u', preg_quote($name));
$result = preg_grep($pattern, $menus);
这段代码创建正则表达式模式并根据它过滤数组。请注意,如果 $name
为空,您将获得所有命中。只是说一下。
所以完整的 foreach
看起来像:
foreach ($names as $i => $name) {
$pattern = sprintf('/%s/u', preg_quote($name));
$result = preg_grep($pattern, $menus);
printf("%d.) %s: %d time(s)\n", $i + 1, $name, count($result));
}
这是示例输出 ( online demo ):
1.) Chicken Pot Pie: 3 time(s)
2.) Tournedos Rossini: 1 time(s)
3.) Beefsteak: 1 time(s)
4.) Tavern Sandwich: 0 time(s)
5.) Fish&Chips: 2 time(s)
因此,这个答案演示了如何将 PHP 中的多个强大基石结合在一起:XML 解析器、XPath 查询、数组处理和正则表达式。
以及此答案完整性的完整示例:
<?php
/**
* How to write a foreach loop in PHP that can count the values of an XML element with a different element?
*
* @link http://stackoverflow.com/a/29219339/367456
*/
$foodsBuffer = <<<XML
<foods total="5">
<food>
<id>5188</id>
<yourfood>
<name>Chicken Pot Pie</name>
</yourfood>
</food>
<food>
<id>5189</id>
<yourfood>
<name>Tournedos Rossini</name>
</yourfood>
</food>
<food>
<id>5190</id>
<yourfood>
<name>Beefsteak</name>
</yourfood>
</food>
<food>
<id>5191</id>
<yourfood>
<name>Tavern Sandwich</name>
</yourfood>
</food>
<food>
<id>5192</id>
<yourfood>
<name>Fish&Chips</name>
</yourfood>
</food>
</foods>
XML;
$weekdaysBuffer = <<<XML
<weekdays total="7">
<day>
<date>01-16-2016</date>
<menu>We have served Beefsteak for today.</menu>
</day>
<day>
<date>01-17-2016</date>
<menu>We have served Fish&Chips for today.</menu>
</day>
<day>
<date>01-18-2016</date>
<menu>Today, there is Chicken Pot Pie for you.</menu>
</day>
<day>
<date>01-19-2016</date>
<menu>Fish&Chips is one of the best foods in our restaurant</menu>
</day>
<day>
<date>01-20-2016</date>
<menu>Welcome home! Tournedos Rossini!</menu>
</day>
<day>
<date>01-21-2016</date>
<menu>Chicken Pot Pie</menu>
</day>
<day>
<date>01-22-2016</date>
<menu>Chicken Pot Pie is one of our most delicious dishes.</menu>
</day>
</weekdays>
XML;
$foods = simplexml_load_string($foodsBuffer);
$weekdays = simplexml_load_string($weekdaysBuffer);
$names = $foods->xpath('/*/food//name');
$menus = $weekdays->xpath('/*/day/menu');
foreach ($names as $i => $name) {
$pattern = sprintf('/%s/u', preg_quote($name));
$result = preg_grep($pattern, $menus);
printf("%d.) %s: %d time(s)\n", $i + 1, $name, count($result));
}
关于php - 如何在 PHP 中编写一个 foreach 循环来计算具有不同元素的 XML 元素的值?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/29212660/