blocks|key|350144|text|我发现这个答案是为了寻找关于我遇到的问题的更多信息。我使用的是包含UTF-8字符的字符串，它不能作为我拥有的数组的键。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|350145|就像这样|350146|$str+=+"R&D+-+Solution";
$arr+=+array(+"R&D+-+Solution"+=>+"Research"+);
echo+$arr[$str];++//+did+not+work|code-block|syntax|javascript|350147|对我来说(不大也不聪明)的解决方案是这样做..|350148|$str+=+md5("R&D+-+Solution");
$arr+=+array(+md5("R&D+-+Solution")+=>+"Research"+);
echo+$arr[$str];++//+works!|350149|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

I found this answer looking for more information on a problem I had. I was using strings with UTF-8 characters in them, which would not work as keys to an array I had.

Something like

<pre><code>$str = "R&amp;D - Solution";
$arr = array( "R&amp;D - Solution" =&gt; "Research" );
echo $arr[$str]; // did not work
</code></pre>

The (not big or clever) solution for me was to do this..

<pre><code>$str = md5("R&amp;D - Solution");
$arr = array( md5("R&amp;D - Solution") =&gt; "Research" );
echo $arr[$str]; // works!
</code></pre>

blocks|key|566047|text|PHP数组键可以是整数或字符串。PHP字符串是字节数组，表示字节序列。没有其他类型的字符串，PHP也不会对数组键字符串施加任何特殊限制。换句话说:只要它是一个字符串，任何东西都可以。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|566048|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

PHP array keys can be integers or strings. PHP strings are byte arrays, meaning sequences of bytes. There are no other types of strings and PHP doesn't otherwise impose any special restrictions on array key strings. In other words: as long as it's a string, anything goes.

blocks|key|350006|text|任何可以填充到PHP字符串中的东西都可以用作数组键。允许的字符数没有限制。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|350007|$a+=+array();

$x+=+'long+string+of+random+garage';
echo+$a[$x];+//+this+is+ok

$x+=+array();
echo+$a[$x];+//+not+ok|code-block|syntax|javascript|350008|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Anything you can stuff into a PHP string can be used as an array key. There's no limit on the characters allowed.

<pre><code>$a = array();

$x = 'long string of random garage';
echo $a[$x]; // this is ok

$x = array();
echo $a[$x]; // not ok
</code></pre>

blocks|key|350258|text|如果复杂的键导致了“未定义的索引”错误，那么您可能只是遇到了“修剪”问题。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|350259|我发疯了，因为一个复杂的键发出了“未定义的索引”错误，我想这可能是一个语法违规。导致错误的数组键是从MySQL数据库查询中的字段构建的，我正在将该查询转换为键并在新数组中使用。关键字看起来像这样：pl_1DNKoiJKwotCqAycickBVhTy，下面是代码是如何构造的。|offset|length|style|CODE|350260|//new+array+created+from+database+query
$new_array[$dbquery['fieldname']]+=+{some+value};

//key+value+found+in+field+of+second+array
$keyval+=+$array_two['fieldname'];

//this+produced+the+"undefined+index"+error
echo+$new_array[$keyval];|code-block|syntax|javascript|350261|实际上，$keyval和$dbquery['fieldname']似乎是完美匹配的(通过在浏览器上回显两者来进行视觉验证)。在第二个声明中简单地使用trim就解开了这个谜团：$keyval+=+trim($array_two['fieldname']);一旦‘修剪’，php就不再抱怨了。|350262|希望这能将其他人从一些令人沮丧的时刻中解救出来。|350263|entityMap^0|0|2Q|R|0|0|4|7|C|L|22|4|2F|14|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@$D|U|E|V|F|G]]|9|@]|A|$]]|$1|H|3|I|5|J|7|W|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|X|8|@$D|Y|E|Z|F|G]|$D|10|E|11|F|G]|$D|12|E|13|F|G]|$D|14|E|15|F|G]]|9|@]|A|$]]|$1|O|3|P|5|6|7|16|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|17|8|@]|9|@]|A|$]]]|R|$]]

If complex keys are causing an "undefined index" error, you may simply have a "trim" problem.

I was going nuts because a complex key was spitting out the "undefined index" error and I thought maybe it was a syntax violation. The array key causing the error was built from a field from a MySQL database query that I was converting into a key and using in a new array. The key looked like this: <code>pl_1DNKoiJKwotCqAycickBVhTy</code> and here's how the code was constructed.

<pre><code>//new array created from database query
$new_array[$dbquery['fieldname']] = {some value};

//key value found in field of second array
$keyval = $array_two['fieldname'];

//this produced the "undefined index" error
echo $new_array[$keyval];
</code></pre>

when, in fact, the <code>$keyval</code> and <code>$dbquery['fieldname']</code> appeared to be a perfect match (visually verified by echoing both to the browser). The mystery was solved by simply using <code>trim</code> in the second statement like this: <code>$keyval = trim($array_two['fieldname']);</code> Once 'trimmed', php no longer complained.

Hoping this saves some others from some frustrating moments...

blocks|key|566019|text|我个人对数组键中的不寻常字符没有任何问题。什么是合法的，什么是不合法的，都没有很好的文档记录，只是说键必须是标量。你最好的办法就是试一试，看看。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|566020|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

I've personally not had any problems with unusual characters in array keys. What is and isn't legal isn't well documented, other than to say that the key must be a scalar. Your best bet is to just try it and see.

blocks|key|566145|text|除了所有的答案，因为它们是正确的:你可以使用PSRs，他们是最好的程序员之间的某种规则，拥有良好的和标准的编码风格。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|566146|entityMap|0|LINK|mutability|MUTABLE|url|http://php-fig.org/^0|M|4|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

In addition to all the answers as they are true: You can use <a href="http://php-fig.org" rel="nofollow noreferrer">PSRs</a> that they are some kind of rules between best programmers for having a nice and standard coding style.

blocks|key|350282|text|在php数组中，不能使用key+:+2.3或十进制数字|type|unstyled|depth|inlineStyleRanges|entityRanges|data|350283|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

In php array you cannot use key : 2.3 or decimal numbers

blocks|key|566182|text|将php页面编码为ANSI+"é“即可使用(Cinéma不会显示为Cin©ma)。在Notepad%2B%2B中，只需使用菜单Encode=>Convert+ANSI并保存|type|unstyled|depth|inlineStyleRanges|entityRanges|data|566183|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Encode the php page in ANSI "é" will be able for use (Cinéma wont show up as CinÃ©ma).
In Notepad++ just use the menu Encode=>Convert ANSI and save

I have some php array keys that are populated with a lot of weird characters.

Is this allowed? Are there any constraints to what I cannot use?

Characters allowed in php array keys?

SQL数据库

数据库

MySQL

我有一些php数组键，里面填充了很多奇怪的字符。这是允许的吗？我不能使用的东西有什么限制吗？

问php数组键中允许的字符？
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