blocks|key|283219|text|你的第二个代码块是正确的。explode和其他函数不能返回完全形成的数组以供立即使用，因此您必须设置一个临时变量。在开发树中可能有代码可以做到这一点，但现在获取所需元素的唯一方法是临时变量。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|283220|entityMap^0|D|7|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

You are correct with your second code-block. <code>explode</code>, and other functions can't return a fully formed array for immediate use,and so you have to set a temporary variable. There may be code in the development tree to do that, but the only way to get the elements you need for now, is the temporary variable.

blocks|key|2999923|text|使用current|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2999924|$a+=+current(explode('s',+$str));|code-block|syntax|javascript|2999925|但我发现这很丑陋|2999926|entityMap|0|LINK|mutability|MUTABLE|url|http://php.net/manual/en/function.current.php^0|2|7|2|7|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@$9|X|A|Y|1|Z]]|E|$]]|$1|F|3|G|5|H|7|10|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|11|8|@]|D|@]|E|$]]|$1|M|3|-4|5|6|7|12|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]]]

use <a href="http://php.net/manual/en/function.current.php" rel="nofollow"><code>current</code></a>

<pre><code>$a = current(explode('s', $str));
</code></pre>

but I found is ugly

blocks|key|285484|text|正如其他人所说，PHP不同于JavaScript，因为它不能从函数返回中访问数组元素。你列出的第二种方法是可行的。您还可以使用current()、reset()或array_pop()函数获取数组的第一个元素，如下所示：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|285485|$a+=+current(+explode(+'s',+$str+)+);+//or
$a+=+reset(+explode(+'s',+$str+)+);+//or
$a+=+array_pop+(+explode(+'s',+$str+)+);|code-block|syntax|javascript|285486|如果您想要消除由于多个分隔可能导致的轻微开销，您可以通过在其他参数后传递两个参数来将其限制设置为2。您也可以考虑使用str_pos和strstr：|285487|$a+=+substr(+$str,+0,+strpos(+$str,+'s'+)+);|285488|这些选项中的任何一个都可以工作。|285489|另一种编辑方式是使用list()+(参见PHP+doc)。有了它，你可以抓取任何元素：|285490|list(+$first+)+=+explode(+'s',+$str+);+//First
list(+,$second+)+=+explode(+'s',+$str+);+//Second
list(+,,$third+)+=+explode(+'s',+$str+);+//Third
//etc.|285491|这不是你的风格？您总是可以编写一个小的辅助函数来从返回数组的函数中获取元素：|285492|function+array_grab(+$arr,+$key+)+{+return(+$arr[$key]+);+}

$part+=+array_grab(+explode(+'s',+$str+),+0+);+//Usage:+1st+element,+etc.|285493|编辑：PHP5.4将支持数组取消引用，因此您将能够执行以下操作：|BOLD|285494|$first_element+=+explode(',','A,B,C')[0];|285495|entityMap|0|LINK|mutability|MUTABLE|url|http://php.net/manual/en/function.list.php^0|1R|9|21|7|29|B|0|0|0|0|0|A|6|K|7|0|0|0|0|0|0|3|0|0^^$0|@$1|2|3|4|5|6|7|1B|8|@$9|1C|A|1D|B|C]|$9|1E|A|1F|B|C]|$9|1G|A|1H|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|1I|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|1J|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|1K|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|1L|8|@]|D|@]|E|$]]|$1|Q|3|R|5|6|7|1M|8|@$9|1N|A|1O|B|C]]|D|@$9|1P|A|1Q|1|1R]]|E|$]]|$1|S|3|T|5|H|7|1S|8|@]|D|@]|E|$I|J]]|$1|U|3|V|5|6|7|1T|8|@]|D|@]|E|$]]|$1|W|3|X|5|H|7|1U|8|@]|D|@]|E|$I|J]]|$1|Y|3|Z|5|6|7|1V|8|@$9|1W|A|1X|B|10]]|D|@]|E|$]]|$1|11|3|12|5|H|7|1Y|8|@]|D|@]|E|$I|J]]|$1|13|3|-4|5|6|7|1Z|8|@]|D|@]|E|$]]]|14|$15|$5|16|17|18|E|$19|1A]]]]

As others have said, PHP is unlike JavaScript in that it can't access array elements from function returns.
The second method you listed works. You can also grab the first element of the array with the <code>current()</code>, <code>reset()</code>, or <code>array_pop()</code> functions like so:

<pre><code>$a = current( explode( 's', $str ) ); //or
$a = reset( explode( 's', $str ) ); //or
$a = array_pop ( explode( 's', $str ) );
</code></pre>

If you would like to remove the slight overhead that explode may cause due to multiple separations, you can set its limit to 2 by passing two after the other arguments. You may also consider using str_pos and strstr instead:

<pre><code>$a = substr( $str, 0, strpos( $str, 's' ) );
</code></pre>

Any of these choices will work.

EDIT Another way would be to use <code>list()</code> (see <a href="http://php.net/manual/en/function.list.php" rel="noreferrer">PHP doc</a>). With it you can grab any element:

<pre><code>list( $first ) = explode( 's', $str ); //First
list( ,$second ) = explode( 's', $str ); //Second
list( ,,$third ) = explode( 's', $str ); //Third
//etc.
</code></pre>

That not your style? You can always write a small helper function to grab elements from functions that return arrays:

<pre><code>function array_grab( $arr, $key ) { return( $arr[$key] ); }

$part = array_grab( explode( 's', $str ), 0 ); //Usage: 1st element, etc.
</code></pre>

EDIT: PHP 5.4 will support array dereferencing, so you will be able to do:

<pre><code>$first_element = explode(',','A,B,C')[0];
</code></pre>

blocks|key|283274|text|您可以使用以下命令：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|283275|$a+=+array_shift(array_slice(explode("s",+$str),+0,+1)));|code-block|syntax|javascript|283276|这是我发现的从explode数组中获取特定元素的最好方法。|283277|细目：|283278|283279|Explode返回一个数组，delimiter|unordered-list-item|offset|length|style|CODE|283280|array_slice($arrayname,+$offset,+$length)返回一个新数组，其中所有项都来自偏移量，lenght|283281|array_shift($array)返回传递给它的数组中的第一个(在本例中是唯一的)项。|283282|283283|这看起来并不美观，但效果与以下内容相同：|283284|$a+=+explode('s',+$str)[0];|283285|肯定有更好的方法来做这件事，但我还没有找到它。|283286|我正在研究这个，因为我想提取的一部分，所以我做了以下测试：|BOLD|283287|function+urlsplitTest()+
{

++++$url+=+'control_panel/deliveryaddress/188/edit/';
++++$passes+=+1000000;

++++Timer::reset();
++++Timer::start();
++++$x+=0;
++++while+($x<$passes)+{
++++++++$res+=+array_shift(array_slice(explode("/",+$url),+2,+1));
++++++++$x%2B%2B;
++++}
++++Timer::stop();
++++$time+=+Timer::get();
++++echo+$res.'<br+/>Time+used+on:+array_shift(array_slice(explode("/",+$url),+2,+++++1)):'.$time;

++++Timer::reset();
++++Timer::start();
++++$x+=0;
++++while+($x<$passes)+{
++++++++$res+=+array_get(explode("/",+$url),+2);
++++++++$x%2B%2B;
++++}
++++Timer::stop();
++++$time+=+Timer::get();
++++echo+$res.'<br+/>Time+used+on:+array_get(explode("/",+$url),+2):+'.$time;

++++Timer::reset();
++++Timer::start();
++++$x+=0;
++++while+($x<$passes)+{
++++++++$res+=+substr($url,+30,+-6);
++++++++$x%2B%2B;
++++}
++++Timer::stop();
++++$time+=+Timer::get();
++++echo+$res.'<br+/>Time+used+on:+substr($url,+30,+-6):+'.$time;
}

function+array_get($array,+$pos)+{return+$array[$pos];}|283288|结果如下：|283289|Time+used+on:+array_shift(array_slice(explode("/",+$url),+2,+1)):7.897379
Time+used+on:+array_get(explode("/",+$url),+2):+2.979483
Time+used+on:+substr($url,+30,+-6):+0.932806|283290|在我的例子中，我想从url中获取数字188，而url的其余部分都是静态的，所以我最终使用了substr方法，但对于长度可能发生变化的动态版本，上面的array_get方法是最简单和最干净的。|283291|entityMap^0|0|0|0|0|0|0|7|0|0|15|0|0|J|0|0|0|0|0|E|F|0|0|0|5|0|0|0|2N|0^^$0|@$1|2|3|4|5|6|7|1G|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|1H|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|1I|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|1J|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|1K|8|@]|9|@]|A|$]]|$1|L|3|M|5|N|7|1L|8|@$O|1M|P|1N|Q|R]]|9|@]|A|$]]|$1|S|3|T|5|N|7|1O|8|@$O|1P|P|1Q|Q|R]]|9|@]|A|$]]|$1|U|3|V|5|N|7|1R|8|@$O|1S|P|1T|Q|R]]|9|@]|A|$]]|$1|W|3|-4|5|6|7|1U|8|@]|9|@]|A|$]]|$1|X|3|Y|5|6|7|1V|8|@]|9|@]|A|$]]|$1|Z|3|10|5|D|7|1W|8|@]|9|@]|A|$E|F]]|$1|11|3|12|5|6|7|1X|8|@]|9|@]|A|$]]|$1|13|3|14|5|6|7|1Y|8|@$O|1Z|P|20|Q|15]]|9|@]|A|$]]|$1|16|3|17|5|D|7|21|8|@]|9|@]|A|$E|F]]|$1|18|3|19|5|6|7|22|8|@$O|23|P|24|Q|15]]|9|@]|A|$]]|$1|1A|3|1B|5|D|7|25|8|@]|9|@]|A|$E|F]]|$1|1C|3|1D|5|6|7|26|8|@$O|27|P|28|Q|15]]|9|@]|A|$]]|$1|1E|3|-4|5|6|7|29|8|@]|9|@]|A|$]]]|1F|$]]

You can use this:

<pre><code>$a = array_shift(array_slice(explode("s", $str), 0, 1)));
</code></pre>

This is the best way I have found to get a specific element from an array from explode.

Breakdown:

<ul>
<li><code>Explode</code> returns an array on delimiter</li>
<li><code>array_slice($arrayname, $offset, $length)</code> gives you a new array with all items from offset, lenght</li>
<li><code>array_shift($array)</code> gives you the first (and in this case, the only) item in the array passed to it.</li>
</ul>

This doesen't look pretty, but does the same as:

<pre><code>$a = explode('s', $str)[0];
</code></pre>

There must be a better way to do this, but I have not found it.

Update:
I was investigating this because I wanted to extract a portion of a URL, so i did the following tests:

<pre><code>function urlsplitTest() 
{

 $url = 'control_panel/deliveryaddress/188/edit/';
 $passes = 1000000;

 Timer::reset();
 Timer::start();
 $x =0;
 while ($x&lt;$passes) {
 $res = array_shift(array_slice(explode("/", $url), 2, 1));
 $x++;
 }
 Timer::stop();
 $time = Timer::get();
 echo $res.'&lt;br /&gt;Time used on: array_shift(array_slice(explode("/", $url), 2, 1)):'.$time;

 Timer::reset();
 Timer::start();
 $x =0;
 while ($x&lt;$passes) {
 $res = array_get(explode("/", $url), 2);
 $x++;
 }
 Timer::stop();
 $time = Timer::get();
 echo $res.'&lt;br /&gt;Time used on: array_get(explode("/", $url), 2): '.$time;

 Timer::reset();
 Timer::start();
 $x =0;
 while ($x&lt;$passes) {
 $res = substr($url, 30, -6);
 $x++;
 }
 Timer::stop();
 $time = Timer::get();
 echo $res.'&lt;br /&gt;Time used on: substr($url, 30, -6): '.$time;
}

function array_get($array, $pos) {return $array[$pos];}
</code></pre>

The results were as following:

<pre><code>Time used on: array_shift(array_slice(explode("/", $url), 2, 1)):7.897379
Time used on: array_get(explode("/", $url), 2): 2.979483
Time used on: substr($url, 30, -6): 0.932806
</code></pre>

In my case i wanted to get the number 188 from the url, and all the rest of the url was static, so i ended up using the substr method, but for a dynamic version where lenth may change, the array_get method above is the fastets and cleanest.

How can I get the following code to work?

<blockquote>
 $a = explode('s', $str)[0];
</blockquote>

I only see solutions looking like this:

<blockquote>
 $a = explode('s', $str); $a=$a[0];
</blockquote>

PHP explode and array index

我怎样才能让下面的代码工作？爆炸$a =  (‘s’，$str)；我只看到这样的解决方案：分解$a =  (‘s’，$str)；$a=$a;

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