如何使用 PHP switch 语句检查字符串是否包含单词（但也可以包含其他单词）？
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How to use a PHP switch statement to check if a string contains a word (but can also contain others)?
提问by sebastian
I'm using a PHP switch to include certain files based on the incoming keywords passed in a parameter of the page's URL.
我正在使用 PHP 开关根据页面 URL 参数中传递的传入关键字来包含某些文件。
The URL, for example, could be: ...page.php?kw=citroen%20berlingo%20keywords
例如，URL 可以是： ...page.php?kw=citroen%20berlingo%20keywords
Inside the page, I'd like to use something like this:
在页面内，我想使用这样的东西：
<?
switch($_GET['kw']){
case "berlingo":
include 'berlingo.php'
break;
case "c4":
include 'c4.php';
break;
}
?>
What I want to do in the first case is include the berlingo.phpfile if the keyword parameter containsberlingo, but it doesn't have to be exactlythat keyword alone.
在第一种情况下，我想要做的是berlingo.php如果关键字参数包含文件，则包含文件berlingo，但它不必仅是该关键字。
For example, I want to include the berlingo.phpfile if the keyword is berlingo, but alsoif it's citroen berlingo.
例如，我想包括的berlingo.php文件，如果关键字berlingo，但也如它的citroen berlingo。
How can I evaluate if a given string contains a value using a PHP case select (switch statement)?
如何使用 PHP case select（switch 语句）评估给定字符串是否包含值？
Thanks.
谢谢。
回答by baacke
Based on this questionand this answer, the solutions I've come up with (while still using a case select) are below.
基于这个问题和这个答案，我想出的解决方案（同时仍然使用案例选择）如下。
You can use either stristr()or strstr(). The reason I chose to use stristr()in this case is simply because it's case-insensitive, and thus, is more robust.
您可以使用stristr()或strstr()。我选择stristr()在这种情况下使用的原因仅仅是因为它不区分大小写，因此更健壮。
Example:
例子：
$linkKW = $_GET['kw'];
switch (true){
case stristr($linkKW,'berlingo'):
include 'berlingo.php';
break;
case stristr($linkKW,'c4'):
include 'c4.php';
break;
}
You could also use stripos()or strpos()if you'd like (thanks, Fractaliste), though I personally find this more difficult to read. Same deal as the other method above; I went the case-insensitiveroute.
如果您愿意，您也可以使用stripos()或strpos() （谢谢，Fractalist），尽管我个人觉得这更难阅读。与上述其他方法相同；我走了不区分大小写的路线。
Example:
例子：
$linkKW = $_GET['kw'];
switch (true){
case stripos($linkKW,'berlingo') !== false:
include 'berlingo.php';
break;
case stripos($linkKW,'c4') !== false:
include 'c4.php';
break;
}
回答by deceze
Since in a switchstatement only a simple equality testing will be performed it won't help you much here. You need to run the string through a string matching function, best suited of which is strpos. The straight forward answer is:
由于在switch语句中只会执行简单的相等性测试，因此在这里对您没有太大帮助。您需要通过字符串匹配函数运行字符串，最适合的是strpos. 直接的答案是：
if (strpos($_GET['kw'], 'berlingo') !== false) {
include 'berlingo.php';
} else if (strpos($_GET['kw'], 'c4') !== false) {
include 'c4.php';
} … and so on …
The more elegant solution would be something like this:
更优雅的解决方案是这样的：
$map = array('berlingo' => 'berlingo.php', 'c4' => 'c4.php', …);
foreach ($map as $keyword => $file) {
if (strpos($_GET['kw'], $keyword) !== false) {
include $file;
break;
}
}
Or, if the correspondence between the keyword and the file is always 1:1:
或者，如果关键字和文件的对应关系始终是 1:1：
$keywords = array('berlingo', 'c4', …);
foreach ($keywords as $keyword) {
if (strpos($_GET['kw'], $keyword) !== false) {
include "$keyword.php";
break;
}
}
回答by chris
$keywords = array('berlingo', 'c4');
foreach($keywords as $keyword)
if(strpos($_GET['kw'], $keyword) !== FALSE)
include("$keyword.php");
I wouldn't recommend including php files based on user input though.
我不建议包含基于用户输入的 php 文件。
回答by AlexIL
You can also use regular expression in switch -> case:
您还可以在 switch -> case 中使用正则表达式：
<?php
$kw = filter_input(INPUT_GET, "kw");
switch($kw){
case (preg_match('/*berlingo*/', $kw) ? true : false):
include 'berlingo.php';
break;
case "c4":
include 'c4.php';
break;
}
?>
回答by codaddict
回答by user1718888
In my opinion, it's a code smellif you're including scripts via GET variables, but you can do this elegantly using a value class with methods whose logic return the value object itself if true.
在我看来，如果您通过 GET 变量包含脚本，这是一种代码异味，但是您可以使用带有方法的值类优雅地做到这一点，这些方法的逻辑返回值对象本身（如果为真）。
The idea is to keep in mind that a switchstatement will execute any code where $switch == $case (a loose match). So just create methods which either return $this, or nothing at all.
这个想法是要记住，switch语句将执行 $switch == $case （松散匹配）的任何代码。因此，只需创建返回$this或什么都不返回的方法。
Example:
例子：
class Haystack {
public $value;
public function __construct($value)
{
$this->value = $value;
}
public function contains($needle):
{
if (strpos($this->value, $needle) !== false)
return $this;
}
}
$kw = new Haystack($_GET['kw']);
switch ($kw) {
case $kw->contains('berlingo'):
require_once 'berlingo.php';
case $kw->contains('c4'):
require_once 'c4.php';
}
You can, of course, generously garnish this code with typehints. If you do, and are not using a version of PHP which supports nullable return types (ie a method signature of public function contains(string $substring): ?Haystack) then your class would have to elaborate to reflect that.
当然，您可以用类型提示慷慨地装饰此代码。如果您这样做，并且不使用支持可为空返回类型（即 的方法签名public function contains(string $substring): ?Haystack）的 PHP 版本，那么您的类将必须详细说明以反映这一点。
Example:
例子：
final class Haystack {
private $value;
private $isMain;
public function __construct(string $value, bool $isMain = true)
{
$this->value = $value;
$this->isMain = $isMain;
}
final public function contains($needle): Haystack
{
if (strpos($this->value, $needle) !== false)
return $this;
return new Haystack($needle, false);
}
}
This way, if your explicit matching logic fails inside the method, if for some reason new Haystack($_GET['kw']) == new Haystack($needle);is true, the non-matching property "$isMain" will ensure they are not evaluated as equal.
这样，如果您的显式匹配逻辑在方法内部失败，如果由于某种原因new Haystack($_GET['kw']) == new Haystack($needle);为真，则非匹配属性“$isMain”将确保它们不被评估为相等。
Again, I would re-examine why you'd want to do this in the first place for this particular situation; traditionally, Composeris a dependency management tool which would be used to include various scripts you need via a PSR autoload standard. That in combination with a Router library would probably be the most useful to address your actual needs.
再次，我会重新检查为什么您首先要针对这种特殊情况执行此操作；传统上，Composer是一种依赖管理工具，可用于通过 PSR 自动加载标准包含您需要的各种脚本。与 Router 库结合使用可能最能满足您的实际需求。
回答by mOrloff
I know this is WAY after the fact, but just as an aside, one can always avoid the loop altogether if expecting a 1:1 relationship.
我知道这是事后的方式，但顺便说一句，如果期望 1:1 的关系，人们总是可以完全避免循环。
Something along the lines of:
类似的东西：
$map = array('berlingo' => 'berlingo.php', 'c4' => 'c4.php', …);
if( !isset( $map[$_GET['kw']] ))
throw new Exception("Blah!!");
include $map[$_GET['kw']];
...just sharing as an FYI for newbies.
...只是作为新手的FYI分享。
回答by Core Xii
strpos()is one for checking if a string contains another string.
strpos()用于检查一个字符串是否包含另一个字符串。
There are other functionsfor checking similarity of strings, etc.
还有其他函数用于检查字符串的相似性等。
A switchwon't do, though, since it compares static expressions against a single value. You'll have to use ifs.
switch但是，A不会这样做，因为它将静态表达式与单个值进行比较。你将不得不使用ifs。
