blocks|key|1490988|text|$arr[$newkey]+=+$arr[$oldkey];
unset($arr[$oldkey]);|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1490989|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>$arr[$newkey] = $arr[$oldkey];
unset($arr[$oldkey]);
</code></pre>

blocks|key|1706306|text|这样做并保留数组的顺序的方法是将数组键放入一个单独的数组中，找到并替换该数组中的键，然后将其与值组合回去。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1706307|这里有一个函数可以做到这一点：|1706308|function+change_key(+$array,+$old_key,+$new_key+)+{

++++if(+!+array_key_exists(+$old_key,+$array+)+)
++++++++return+$array;

++++$keys+=+array_keys(+$array+);
++++$keys[+array_search(+$old_key,+$keys+)+]+=+$new_key;

++++return+array_combine(+$keys,+$array+);
}|code-block|syntax|javascript|1706309|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

The way you would do this and preserve the ordering of the array is by putting the array keys into a separate array, find and replace the key in that array and then combine it back with the values. 

Here is a function that does just that:

<pre><code>function change_key( $array, $old_key, $new_key ) {

 if( ! array_key_exists( $old_key, $array ) )
 return $array;

 $keys = array_keys( $array );
 $keys[ array_search( $old_key, $keys ) ] = $new_key;

 return array_combine( $keys, $array );
}
</code></pre>

blocks|key|1491026|text|如果您的array是通过数据库查询构建的，则可以直接从mysql语句更改键：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1491027|而不是|1491028|"select+´id´+from+´tablename´..."|code-block|syntax|javascript|1491029|使用像这样的东西：|1491030|"select+´id´+**as+NEWNAME**+from+´tablename´..."|1491031|entityMap^0|4|5|R|5|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|X|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|Y|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|Z|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|10|8|@]|D|@]|E|$K|L]]|$1|Q|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|R|$]]

if your <code>array</code> is built from a database query, you can change the key directly from the <code>mysql</code> statement:

instead of

<pre><code>"select ´id´ from ´tablename´..."
</code></pre>

use something like:

<pre><code>"select ´id´ **as NEWNAME** from ´tablename´..."
</code></pre>

blocks|key|1491085|text|KernelM的回答很好，但是为了避免Greg在注释中提出的问题(冲突的键)，使用新的数组会更安全|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1491086|$newarr[$newkey]+=+$oldarr[$oldkey];
$oldarr=$newarr;
unset($newarr);|code-block|syntax|javascript|1491087|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|$]]

The answer from KernelM is nice, but in order to avoid the issue raised by Greg in the comment (conflicting keys), using a new array would be safer

<pre><code>$newarr[$newkey] = $oldarr[$oldkey];
$oldarr=$newarr;
unset($newarr);
</code></pre>

blocks|key|1491301|text|$array+=+[
++++'old1'+=>+1
++++'old2'+=>+2
];

$renameMap+=+[
++++'old1'+=>+'new1',+++
++++'old2'+=>+'new2'
];

$array+=+array_combine(array_map(function($el)+use+($renameMap)+{
++++return+$renameMap[$el];
},+array_keys($array)),+array_values($array));

/*
$array+=+[
++++'new1'+=>+1
++++'new2'+=>+2
];
*/|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1491302|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>$array = [
 'old1' =&gt; 1
 'old2' =&gt; 2
];

$renameMap = [
 'old1' =&gt; 'new1', 
 'old2' =&gt; 'new2'
];

$array = array_combine(array_map(function($el) use ($renameMap) {
 return $renameMap[$el];
}, array_keys($array)), array_values($array));

/*
$array = [
 'new1' =&gt; 1
 'new2' =&gt; 2
];
*/
</code></pre>

blocks|key|1706340|text|如果您还希望新数组键的位置与旧数组键的位置相同，则可以这样做：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1706341|function+change_array_key(+$array,+$old_key,+$new_key)+{
++++if(!is_array($array)){+print+'You+must+enter+a+array+as+a+haystack!';+exit;+}
++++if(!array_key_exists($old_key,+$array)){
++++++++return+$array;
++++}

++++$key_pos+=+array_search($old_key,+array_keys($array));
++++$arr_before+=+array_slice($array,+0,+$key_pos);
++++$arr_after+=+array_slice($array,+$key_pos+%2B+1);
++++$arr_renamed+=+array($new_key+=>+$array[$old_key]);

++++return+$arr_before+%2B+$arr_renamed+%2B+$arr_after;
}|code-block|syntax|javascript|1706342|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|$]]

If you want also the position of the new array key to be the same as the old one you can do this:

<pre><code>function change_array_key( $array, $old_key, $new_key) {
 if(!is_array($array)){ print 'You must enter a array as a haystack!'; exit; }
 if(!array_key_exists($old_key, $array)){
 return $array;
 }

 $key_pos = array_search($old_key, array_keys($array));
 $arr_before = array_slice($array, 0, $key_pos);
 $arr_after = array_slice($array, $key_pos + 1);
 $arr_renamed = array($new_key =&gt; $array[$old_key]);

 return $arr_before + $arr_renamed + $arr_after;
}
</code></pre>

blocks|key|1491197|text|如果你的数组是递归的，你可以使用这个函数:测试这个数据：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1491198|++++$datos+=+array
++++(
++++++++'0'+=>+array
++++++++++++(
++++++++++++++++'no'+=>+1,
++++++++++++++++'id_maquina'+=>+1,
++++++++++++++++'id_transaccion'+=>+1276316093,
++++++++++++++++'ultimo_cambio'+=>+'asdfsaf',
++++++++++++++++'fecha_ultimo_mantenimiento'+=>+1275804000,
++++++++++++++++'mecanico_ultimo_mantenimiento'+=>'asdfas',
++++++++++++++++'fecha_ultima_reparacion'+=>+1275804000,
++++++++++++++++'mecanico_ultima_reparacion'+=>+'sadfasf',
++++++++++++++++'fecha_siguiente_mantenimiento'+=>+1275804000,
++++++++++++++++'fecha_ultima_falla'+=>+0,
++++++++++++++++'total_fallas'+=>+0,
++++++++++++),

++++++++'1'+=>+array
++++++++++++(
++++++++++++++++'no'+=>+2,
++++++++++++++++'id_maquina'+=>+2,
++++++++++++++++'id_transaccion'+=>+1276494575,
++++++++++++++++'ultimo_cambio'+=>+'xx',
++++++++++++++++'fecha_ultimo_mantenimiento'+=>+1275372000,
++++++++++++++++'mecanico_ultimo_mantenimiento'+=>+'xx',
++++++++++++++++'fecha_ultima_reparacion'+=>+1275458400,
++++++++++++++++'mecanico_ultima_reparacion'+=>+'xx',
++++++++++++++++'fecha_siguiente_mantenimiento'+=>+1275372000,
++++++++++++++++'fecha_ultima_falla'+=>+0,
++++++++++++++++'total_fallas'+=>+0,
++++++++++++)
++++);|code-block|syntax|javascript|1491199|下面是函数：|1491200|function+changekeyname($array,+$newkey,+$oldkey)
{
+++foreach+($array+as+$key+=>+$value)+
+++{
++++++if+(is_array($value))
+++++++++$array[$key]+=+changekeyname($value,$newkey,$oldkey);
++++++else
++++++++{
+++++++++++++$array[$newkey]+=++$array[$oldkey];++++
++++++++}

+++}
+++unset($array[$oldkey]);++++++++++
+++return+$array;+++
}|1491201|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

If your array is recursive you can use this function:
test this data:

<pre><code> $datos = array
 (
 '0' =&gt; array
 (
 'no' =&gt; 1,
 'id_maquina' =&gt; 1,
 'id_transaccion' =&gt; 1276316093,
 'ultimo_cambio' =&gt; 'asdfsaf',
 'fecha_ultimo_mantenimiento' =&gt; 1275804000,
 'mecanico_ultimo_mantenimiento' =&gt;'asdfas',
 'fecha_ultima_reparacion' =&gt; 1275804000,
 'mecanico_ultima_reparacion' =&gt; 'sadfasf',
 'fecha_siguiente_mantenimiento' =&gt; 1275804000,
 'fecha_ultima_falla' =&gt; 0,
 'total_fallas' =&gt; 0,
 ),

 '1' =&gt; array
 (
 'no' =&gt; 2,
 'id_maquina' =&gt; 2,
 'id_transaccion' =&gt; 1276494575,
 'ultimo_cambio' =&gt; 'xx',
 'fecha_ultimo_mantenimiento' =&gt; 1275372000,
 'mecanico_ultimo_mantenimiento' =&gt; 'xx',
 'fecha_ultima_reparacion' =&gt; 1275458400,
 'mecanico_ultima_reparacion' =&gt; 'xx',
 'fecha_siguiente_mantenimiento' =&gt; 1275372000,
 'fecha_ultima_falla' =&gt; 0,
 'total_fallas' =&gt; 0,
 )
 );
</code></pre>

here is the function:

<pre><code>function changekeyname($array, $newkey, $oldkey)
{
 foreach ($array as $key =&gt; $value) 
 {
 if (is_array($value))
 $array[$key] = changekeyname($value,$newkey,$oldkey);
 else
 {
 $array[$newkey] = $array[$oldkey]; 
 }

 }
 unset($array[$oldkey]); 
 return $array; 
}
</code></pre>

blocks|key|1491614|text|两种解决方案的简单基准比较。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1491615|解决方案1复制和删除(订单丢失，但速度更快)+https://stackoverflow.com/a/240676/1617857|offset|length|1491616|<?php
$array+=+['test'+=>+'value',+['etc...']];

$array['test2']+=+$array['test'];
unset($array['test']);|code-block|syntax|javascript|1491617|解决方案2将密钥重命名为https://stackoverflow.com/a/21299719/1617857|1491618|<?php
$array+=+['test'+=>+'value',+['etc...']];

$keys+=+array_keys(+$array+);
$keys[array_search('test',+$keys,+true)]+=+'test2';
array_combine(+$keys,+$array+);|1491619|基准：|1491620|<?php
$array+=+['test'+=>+'value',+['etc...']];


for+($i+=0;+$i+<+100000000;+$i%2B%2B){
++++//+Solution+1
}


for+($i+=0;+$i+<+100000000;+$i%2B%2B){
++++//+Solution+2
}|1491621|结果：|1491622|php+solution1.php++6.33s++user+0.02s+system+99%25+cpu+6.356++total
php+solution1.php++6.37s++user+0.01s+system+99%25+cpu+6.390++total
php+solution2.php++12.14s+user+0.01s+system+99%25+cpu+12.164+total
php+solution2.php++12.57s+user+0.03s+system+99%25+cpu+12.612+total|1491623|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/240676/1617857|1|https://stackoverflow.com/a/21299719/1617857^0|0|N|16|0|0|0|C|18|1|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|16|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|17|8|@]|9|@$D|18|E|19|1|1A]]|A|$]]|$1|F|3|G|5|H|7|1B|8|@]|9|@]|A|$I|J]]|$1|K|3|L|5|6|7|1C|8|@]|9|@$D|1D|E|1E|1|1F]]|A|$]]|$1|M|3|N|5|H|7|1G|8|@]|9|@]|A|$I|J]]|$1|O|3|P|5|6|7|1H|8|@]|9|@]|A|$]]|$1|Q|3|R|5|H|7|1I|8|@]|9|@]|A|$I|J]]|$1|S|3|T|5|6|7|1J|8|@]|9|@]|A|$]]|$1|U|3|V|5|H|7|1K|8|@]|9|@]|A|$I|J]]|$1|W|3|-4|5|6|7|1L|8|@]|9|@]|A|$]]]|X|$Y|$5|Z|10|11|A|$12|13]]|14|$5|Z|10|11|A|$12|15]]]]

Simple benchmark comparison of both solution.
Solution 1 Copy and remove (order lost, but way faster) <a href="https://stackoverflow.com/a/240676/1617857">https://stackoverflow.com/a/240676/1617857</a>
<pre><code>&lt;?php
$array = ['test' =&gt; 'value', ['etc...']];

$array['test2'] = $array['test'];
unset($array['test']);
</code></pre>
Solution 2 Rename the key <a href="https://stackoverflow.com/a/21299719/1617857">https://stackoverflow.com/a/21299719/1617857</a>
<pre><code>&lt;?php
$array = ['test' =&gt; 'value', ['etc...']];

$keys = array_keys( $array );
$keys[array_search('test', $keys, true)] = 'test2';
array_combine( $keys, $array );
</code></pre>
Benchmark:
<pre><code>&lt;?php
$array = ['test' =&gt; 'value', ['etc...']];


for ($i =0; $i &lt; 100000000; $i++){
 // Solution 1
}


for ($i =0; $i &lt; 100000000; $i++){
 // Solution 2
}
</code></pre>
Results:
<pre><code>php solution1.php 6.33s user 0.02s system 99% cpu 6.356 total
php solution1.php 6.37s user 0.01s system 99% cpu 6.390 total
php solution2.php 12.14s user 0.01s system 99% cpu 12.164 total
php solution2.php 12.57s user 0.03s system 99% cpu 12.612 total
</code></pre>

blocks|key|1706227|text|我喜欢KernelM的解决方案，但我需要一些东西来处理潜在的键冲突(新的键可能与现有的键匹配)。这是我想出来的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1706228|function+swapKeys(+&$arr,+$origKey,+$newKey,+&$pendingKeys+)+{
++++if(+!isset(+$arr[$newKey]+)+)+{
++++++++$arr[$newKey]+=+$arr[$origKey];
++++++++unset(+$arr[$origKey]+);
++++++++if(+isset(+$pendingKeys[$origKey]+)+)+{
++++++++++++//+recursion+to+handle+conflicting+keys+with+conflicting+keys
++++++++++++swapKeys(+$arr,+$pendingKeys[$origKey],+$origKey,+$pendingKeys+);
++++++++++++unset(+$pendingKeys[$origKey]+);
++++++++}
++++}+elseif(+$newKey+!=+$origKey+)+{
++++++++$pendingKeys[$newKey]+=+$origKey;
++++}
}|code-block|syntax|javascript|1706229|然后，您可以像这样循环遍历数组：|1706230|$myArray+=+array(+'1970-01-01+00:00:01',+'1970-01-01+00:01:00'+);
$pendingKeys+=+array();
foreach(+$myArray+as+$key+=>+$myArrayValue+)+{
++++//+NOTE:+strtotime(+'1970-01-01+00:00:01'+)+=+1+(a+conflicting+key)
++++$timestamp+=+strtotime(+$myArrayValue+);
++++swapKeys(+$myArray,+$key,+$timestamp,+$pendingKeys+);
}
//+RESULT:+$myArray+==+array(+1=>'1970-01-01+00:00:01',+60=>'1970-01-01+00:01:00'+)|1706231|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I like KernelM's solution, but I needed something that would handle potential key conflicts (where a new key may match an existing key). Here is what I came up with:

<pre><code>function swapKeys( &amp;$arr, $origKey, $newKey, &amp;$pendingKeys ) {
 if( !isset( $arr[$newKey] ) ) {
 $arr[$newKey] = $arr[$origKey];
 unset( $arr[$origKey] );
 if( isset( $pendingKeys[$origKey] ) ) {
 // recursion to handle conflicting keys with conflicting keys
 swapKeys( $arr, $pendingKeys[$origKey], $origKey, $pendingKeys );
 unset( $pendingKeys[$origKey] );
 }
 } elseif( $newKey != $origKey ) {
 $pendingKeys[$newKey] = $origKey;
 }
}
</code></pre>

You can then cycle through an array like this:

<pre><code>$myArray = array( '1970-01-01 00:00:01', '1970-01-01 00:01:00' );
$pendingKeys = array();
foreach( $myArray as $key =&gt; $myArrayValue ) {
 // NOTE: strtotime( '1970-01-01 00:00:01' ) = 1 (a conflicting key)
 $timestamp = strtotime( $myArrayValue );
 swapKeys( $myArray, $key, $timestamp, $pendingKeys );
}
// RESULT: $myArray == array( 1=&gt;'1970-01-01 00:00:01', 60=&gt;'1970-01-01 00:01:00' )
</code></pre>

blocks|key|1706369|text|此代码将有助于将旧密钥更改为新密钥|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1706370|$i+=+0;
$keys_array=array("0"=>"one","1"=>"two");

$keys+=+array_keys($keys_array);

for($i=0;$i<count($keys);$i%2B%2B)+{
++++$keys_array[$keys_array[$i]]=$keys_array[$i];
++++unset($keys_array[$i]);
}
print_r($keys_array);|code-block|syntax|javascript|1706371|显示如下|1706372|$keys_array=array("one"=>"one","two"=>"two");|1706373|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

this code will help to change the oldkey to new one

<pre><code>$i = 0;
$keys_array=array("0"=&gt;"one","1"=&gt;"two");

$keys = array_keys($keys_array);

for($i=0;$i&lt;count($keys);$i++) {
 $keys_array[$keys_array[$i]]=$keys_array[$i];
 unset($keys_array[$i]);
}
print_r($keys_array);
</code></pre>

display like

<pre><code>$keys_array=array("one"=&gt;"one","two"=&gt;"two");
</code></pre>

blocks|key|1706569|text|您可以基于array_walk使用此函数：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1706570|function+mapToIDs($array,+$id_field_name+=+'id')
{
++++$result+=+[];
++++array_walk($array,+
++++++++function(&$value,+$key)+use+(&$result,+$id_field_name)
++++++++{
++++++++++++$result[$value[$id_field_name]]+=+$value;
++++++++}
++++);
++++return+$result;
}

$arr+=+[0+=>+['id'+=>+'one',+'fruit'+=>+'apple'],+1+=>+['id'+=>+'two',+'fruit'+=>+'banana']];
print_r($arr);
print_r(mapToIDs($arr));|code-block|syntax|javascript|1706571|它提供了：|1706572|Array(
++++[0]+=>+Array(
++++++++[id]+=>+one
++++++++[fruit]+=>+apple
++++)
++++[1]+=>+Array(
++++++++[id]+=>+two
++++++++[fruit]+=>+banana
++++)
)

Array(
++++[one]+=>+Array(
++++++++[id]+=>+one
++++++++[fruit]+=>+apple
++++)
++++[two]+=>+Array(
++++++++[id]+=>+two
++++++++[fruit]+=>+banana
++++)
)|1706573|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

You can use this function based on array_walk:

<pre><code>function mapToIDs($array, $id_field_name = 'id')
{
 $result = [];
 array_walk($array, 
 function(&amp;$value, $key) use (&amp;$result, $id_field_name)
 {
 $result[$value[$id_field_name]] = $value;
 }
 );
 return $result;
}

$arr = [0 =&gt; ['id' =&gt; 'one', 'fruit' =&gt; 'apple'], 1 =&gt; ['id' =&gt; 'two', 'fruit' =&gt; 'banana']];
print_r($arr);
print_r(mapToIDs($arr));
</code></pre>

It gives:

<pre><code>Array(
 [0] =&gt; Array(
 [id] =&gt; one
 [fruit] =&gt; apple
 )
 [1] =&gt; Array(
 [id] =&gt; two
 [fruit] =&gt; banana
 )
)

Array(
 [one] =&gt; Array(
 [id] =&gt; one
 [fruit] =&gt; apple
 )
 [two] =&gt; Array(
 [id] =&gt; two
 [fruit] =&gt; banana
 )
)
</code></pre>

blocks|key|1706518|text|在处理完整的数组时，有一种替代方法可以更改数组元素的键-而无需更改数组的顺序。它只是将数组复制到一个新的数组中。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1706519|例如，我正在处理一个包含索引键和关联键的混合多维数组，我希望在不破坏顺序的情况下用它们的值替换整数键。|1706520|我通过切换所有数字数组条目的键/值来做到这一点-这里：'0'=>'foo‘。请注意，订单是完整的。|1706521|<?php
$arr+=+[
++++'foo',
++++'bar'=>'alfa',
++++'baz'=>['a'=>'hello',+'b'=>'world'],
];

foreach($arr+as+$k=>$v)+{
++++$kk+=+is_numeric($k)+?+$v+:+$k;
++++$vv+=+is_numeric($k)+?+null+:+$v;
++++$arr2[$kk]+=+$vv;
}

print_r($arr2);|code-block|syntax|javascript|1706522|输出：|1706523|Array+(
++++[foo]+=>+
++++[bar]+=>+alfa
++++[baz]+=>+Array+(
++++++++++++[a]+=>+hello
++++++++++++[b]+=>+world
++++++++)
)|1706524|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|S|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|T|8|@]|9|@]|A|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|H|7|V|8|@]|9|@]|A|$I|J]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

There is an alternative way to change the key of an array element when working with a full array - without changing the order of the array.
It's simply to copy the array into a new array.

For instance, I was working with a mixed, multi-dimensional array that contained indexed and associative keys - and I wanted to replace the integer keys with their values, without breaking the order.

I did so by switching key/value for all numeric array entries - here: ['0'=>'foo']. Note that the order is intact.

<pre><code>&lt;?php
$arr = [
 'foo',
 'bar'=&gt;'alfa',
 'baz'=&gt;['a'=&gt;'hello', 'b'=&gt;'world'],
];

foreach($arr as $k=&gt;$v) {
 $kk = is_numeric($k) ? $v : $k;
 $vv = is_numeric($k) ? null : $v;
 $arr2[$kk] = $vv;
}

print_r($arr2);
</code></pre>

Output:

<pre><code>Array (
 [foo] =&gt; 
 [bar] =&gt; alfa
 [baz] =&gt; Array (
 [a] =&gt; hello
 [b] =&gt; world
 )
)
</code></pre>

blocks|key|1491768|text|此函数将通过结合索引搜索来重命名数组键，并保持其位置不变。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1491769|function+renameArrKey($arr,+$oldKey,+$newKey){
++++if(!isset($arr[$oldKey]))+return+$arr;+//+Failsafe
++++$keys+=+array_keys($arr);
++++$keys[array_search($oldKey,+$keys)]+=+$newKey;
++++$newArr+=+array_combine($keys,+$arr);
++++return+$newArr;
}|code-block|syntax|javascript|1491770|用法：|1491771|$arr+=+renameArrKey($arr,+'old_key',+'new_key');|1491772|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

This function will rename an array key, keeping its position, by combining with index searching.

<pre><code>function renameArrKey($arr, $oldKey, $newKey){
 if(!isset($arr[$oldKey])) return $arr; // Failsafe
 $keys = array_keys($arr);
 $keys[array_search($oldKey, $keys)] = $newKey;
 $newArr = array_combine($keys, $arr);
 return $newArr;
}
</code></pre>

Usage:

<pre><code>$arr = renameArrKey($arr, 'old_key', 'new_key');
</code></pre>

blocks|key|1491325|text|这适用于重命名第一个键：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1491326|$a+=+['catine'+=>+'cat',+'canine'++=>+'dog'];
$tmpa['feline']+=+$a['catine'];
unset($a['catine']);
$a+=+$tmpa+%2B+$a;|code-block|syntax|javascript|1491327|然后，print_r($a)呈现一个修复后的有序数组：|1491328|Array
(
++++[feline]+=>+cat
++++[canine]+=>+dog
)|1491329|这适用于重命名任意键：|1491330|$a+=+['canine'++=>+'dog',+'catine'+=>+'cat',+'porcine'+=>+'pig']
$af+=+array_flip($a)
$af['cat']+=+'feline';
$a+=+array_flip($af)|1491331|print_r($a)|1491332|Array
(
++++[canine]+=>+dog
++++[feline]+=>+cat
++++[porcine]+=>+pig
)|1491333|一个广义函数：|1491334|function+renameKey($oldkey,+$newkey,+$array)+{
++++$val+=+$array[$oldkey];
++++$tmp_A+=+array_flip($array);
++++$tmp_A[$val]+=+$newkey;

++++return+array_flip($tmp_A);
}|1491335|entityMap^0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|10|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|12|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|13|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|14|8|@]|9|@]|A|$]]|$1|Q|3|R|5|D|7|15|8|@]|9|@]|A|$E|F]]|$1|S|3|T|5|6|7|16|8|@]|9|@]|A|$]]|$1|U|3|V|5|D|7|17|8|@]|9|@]|A|$E|F]]|$1|W|3|-4|5|6|7|18|8|@]|9|@]|A|$]]]|X|$]]

this works for renaming the first key:

<pre><code>$a = ['catine' =&gt; 'cat', 'canine' =&gt; 'dog'];
$tmpa['feline'] = $a['catine'];
unset($a['catine']);
$a = $tmpa + $a;
</code></pre>

then, print_r($a) renders a repaired in-order array:

<pre><code>Array
(
 [feline] =&gt; cat
 [canine] =&gt; dog
)
</code></pre>

this works for renaming an arbitrary key:

<pre><code>$a = ['canine' =&gt; 'dog', 'catine' =&gt; 'cat', 'porcine' =&gt; 'pig']
$af = array_flip($a)
$af['cat'] = 'feline';
$a = array_flip($af)
</code></pre>

print_r($a)

<pre><code>Array
(
 [canine] =&gt; dog
 [feline] =&gt; cat
 [porcine] =&gt; pig
)
</code></pre>

a generalized function:

<pre><code>function renameKey($oldkey, $newkey, $array) {
 $val = $array[$oldkey];
 $tmp_A = array_flip($array);
 $tmp_A[$val] = $newkey;

 return array_flip($tmp_A);
}
</code></pre>

blocks|key|1706426|text|如果您想一次替换多个密钥(保持顺序)：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1706427|/**
+*+Rename+keys+of+an+array
+*+@param+array+$array+(asoc)
+*+@param+array+$replacement_keys+(indexed)
+*+@return+array
+*/
function+rename_keys($array,+$replacement_keys)++{
++++++return+array_combine($replacement_keys,+array_values($array));
}|code-block|syntax|javascript|1706428|用法：|1706429|$myarr+=+array("a"+=>+22,+"b"+=>+144,+"c"+=>+43);
$newkeys+=+array("x","y","z");
print_r(rename_keys($myarr,+$newkeys));
//must+return:+array("x"+=>+22,+"y"+=>+144,+"z"+=>+43);|1706430|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

If you want to replace several keys at once (preserving order):

<pre><code>/**
 * Rename keys of an array
 * @param array $array (asoc)
 * @param array $replacement_keys (indexed)
 * @return array
 */
function rename_keys($array, $replacement_keys) {
 return array_combine($replacement_keys, array_values($array));
}
</code></pre>

Usage:

<pre><code>$myarr = array("a" =&gt; 22, "b" =&gt; 144, "c" =&gt; 43);
$newkeys = array("x","y","z");
print_r(rename_keys($myarr, $newkeys));
//must return: array("x" =&gt; 22, "y" =&gt; 144, "z" =&gt; 43);
</code></pre>

blocks|key|1491528|text|最好的方法是使用引用，而不是使用unset+(这会进行另一个步骤来清理内存)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1491529|$tab+=+['two'+=>+[]+];|code-block|syntax|javascript|1491530|解决方案：|1491531|$tab['newname']+=+&+$tab['two'];|1491532|您有一个原始名称和一个具有新名称的引用。|1491533|或者，如果您不想在一个值中包含两个名称，则可以创建另一个tab，然后在引用时使用foreach|1491534|foreach($tab+as+$key=>+&+$value)+{
++++if($key=='two')+{+
++++++++$newtab["newname"]+=+&+$tab[$key];
+++++}+else+{
++++++++$newtab[$key]+=+&+$tab[$key];
+++++}
}|1491535|如果你有像100行%2B%2B%2B这样的长数据，迭代比克隆所有的数组和清理旧的数组更好。|1491536|entityMap^0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|Y|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|Z|8|@]|9|@]|A|$]]|$1|O|3|P|5|D|7|10|8|@]|9|@]|A|$E|F]]|$1|Q|3|R|5|6|7|11|8|@]|9|@]|A|$]]|$1|S|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|T|$]]

best way is using reference, and not using unset (which make another step to clean memory)

<pre><code>$tab = ['two' =&gt; [] ];
</code></pre>

solution: 

<pre><code>$tab['newname'] = &amp; $tab['two'];
</code></pre>

you have one original and one reference with new name.

or if you don't want have two names in one value is good make another tab and foreach on reference

<pre><code>foreach($tab as $key=&gt; &amp; $value) {
 if($key=='two') { 
 $newtab["newname"] = &amp; $tab[$key];
 } else {
 $newtab[$key] = &amp; $tab[$key];
 }
}
</code></pre>

Iterration is better on keys than clone all array, and cleaning old array if you have long data like 100 rows +++ etc..

blocks|key|1706764|text|这个基本函数处理交换数组键并保持数组的原始顺序...|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1706765|public+function+keySwap(array+$resource,+array+$keys)
{
++++$newResource+=+[];

++++foreach($resource+as+$k+=>+$r){
++++++++if(array_key_exists($k,$keys)){
++++++++++++$newResource[$keys[$k]]+=+$r;
++++++++}else{
++++++++++++$newResource[$k]+=+$r;
++++++++}
++++}

++++return+$newResource;
}|code-block|syntax|javascript|1706766|然后，您可以循环遍历并将所有'a‘键与'z’键交换，例如...|1706767|$inputs+=+[
++0+=>+['a'=>'1','b'=>'2'],
++1+=>+['a'=>'3','b'=>'4']
]

$keySwap+=+['a'=>'z'];

foreach($inputs+as+$k=>$i){
++++$inputs[$k]+=+$this->keySwap($i,$keySwap);
}|1706768|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

This basic function handles swapping array keys and keeping the array in the original order...

<pre><code>public function keySwap(array $resource, array $keys)
{
 $newResource = [];

 foreach($resource as $k =&gt; $r){
 if(array_key_exists($k,$keys)){
 $newResource[$keys[$k]] = $r;
 }else{
 $newResource[$k] = $r;
 }
 }

 return $newResource;
}
</code></pre>

You could then loop through and swap all 'a' keys with 'z' for example...

<pre><code>$inputs = [
 0 =&gt; ['a'=&gt;'1','b'=&gt;'2'],
 1 =&gt; ['a'=&gt;'3','b'=&gt;'4']
]

$keySwap = ['a'=&gt;'z'];

foreach($inputs as $k=&gt;$i){
 $inputs[$k] = $this-&gt;keySwap($i,$keySwap);
}
</code></pre>

blocks|key|1491399|text|嗯，我之前没有测试过，但我认为这段代码可以工作|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1491400|function+replace_array_key($data)+{
++++$mapping+=+[
++++++++'old_key_1'+=>+'new_key_1',
++++++++'old_key_2'+=>+'new_key_2',
++++];

++++$data+=+json_encode($data);
++++foreach+($mapping+as+$needed+=>+$replace)+{
++++++++$data+=+str_replace('"'.$needed.'":',+'"'.$replace.'":',+$data);
++++}

++++return+json_decode($data,+true);
}|code-block|syntax|javascript|1491401|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|$]]

Hmm, I'm not test before, but I think this code working

<pre><code>function replace_array_key($data) {
 $mapping = [
 'old_key_1' =&gt; 'new_key_1',
 'old_key_2' =&gt; 'new_key_2',
 ];

 $data = json_encode($data);
 foreach ($mapping as $needed =&gt; $replace) {
 $data = str_replace('"'.$needed.'":', '"'.$replace.'":', $data);
 }

 return json_decode($data, true);
}
</code></pre>

blocks|key|1491481|text|它保留了简单易懂的顺序：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1491482|function+rename_array_key(array+$array,+$old_key,+$new_key)+{
++if+(!array_key_exists($old_key,+$array))+{
++++++return+$array;
++}
++$new_array+=+[];
++foreach+($array+as+$key+=>+$value)+{
++++$new_key+=+$old_key+===+$key
++++++?+$new_key
++++++:+$key;
++++$new_array[$new_key]+=+$value;
++}
++return+$new_array;
}|code-block|syntax|javascript|1491483|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|$]]

One which preservers ordering that's simple to understand:

<pre><code>function rename_array_key(array $array, $old_key, $new_key) {
 if (!array_key_exists($old_key, $array)) {
 return $array;
 }
 $new_array = [];
 foreach ($array as $key =&gt; $value) {
 $new_key = $old_key === $key
 ? $new_key
 : $key;
 $new_array[$new_key] = $value;
 }
 return $new_array;
}
</code></pre>

blocks|key|1491577|text|您可以编写简单的函数，将回调应用于给定数组的键。类似于array_map|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1491578|<?php
function+array_map_keys(callable+$callback,+array+$array)+{
++++return+array_merge([],+...array_map(
++++++++function+($key,+$value)+use+($callback)+{+return+[$callback($key)+=>+$value];+},
++++++++array_keys($array),
++++++++$array
++++));
}

$array+=+['a'+=>+1,+'b'+=>+'test',+'c'+=>+['x'+=>+1,+'y'+=>+2]];
$newArray+=+array_map_keys(function($key)+{+return+'new'+.+ucfirst($key);+},+$array);

echo+json_encode($array);+//+{"a":1,"b":"test","c":{"x":1,"y":2}}
echo+json_encode($newArray);+//+{"newA":1,"newB":"test","newC":{"x":1,"y":2}}|code-block|syntax|javascript|1491579|这是一个要点https://gist.github.com/vardius/650367e15abfb58bcd72ca47eff096ca#file-array_map_keys-php。|1491580|entityMap|0|LINK|mutability|MUTABLE|url|https://www.php.net/manual/en/function.array-map.php|1|https://gist.github.com/vardius/650367e15abfb58bcd72ca47eff096ca#file-array_map_keys-php^0|R|9|0|0|0|6|2G|1|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@$A|V|B|W|1|X]]|C|$]]|$1|D|3|E|5|F|7|Y|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|Z|8|@]|9|@$A|10|B|11|1|12]]|C|$]]|$1|K|3|-4|5|6|7|13|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]|S|$5|N|O|P|C|$Q|T]]]]

You can write simple function that applies the callback to the keys of the given array. Similar to <a href="https://www.php.net/manual/en/function.array-map.php" rel="nofollow noreferrer">array_map</a>

<pre><code>&lt;?php
function array_map_keys(callable $callback, array $array) {
 return array_merge([], ...array_map(
 function ($key, $value) use ($callback) { return [$callback($key) =&gt; $value]; },
 array_keys($array),
 $array
 ));
}

$array = ['a' =&gt; 1, 'b' =&gt; 'test', 'c' =&gt; ['x' =&gt; 1, 'y' =&gt; 2]];
$newArray = array_map_keys(function($key) { return 'new' . ucfirst($key); }, $array);

echo json_encode($array); // {"a":1,"b":"test","c":{"x":1,"y":2}}
echo json_encode($newArray); // {"newA":1,"newB":"test","newC":{"x":1,"y":2}}
</code></pre>

Here is a gist <a href="https://gist.github.com/vardius/650367e15abfb58bcd72ca47eff096ca#file-array_map_keys-php" rel="nofollow noreferrer">https://gist.github.com/vardius/650367e15abfb58bcd72ca47eff096ca#file-array_map_keys-php</a>.

I have an associative array in the form <code>key =&gt; value</code> where key is a numerical value, however it is not a sequential numerical value. The key is actually an ID number and the value is a count. This is fine for most instances, however I want a function that gets the human-readable name of the array and uses that for the key, without changing the value.

I didn't see a function that does this, but I'm assuming I need to provide the old key and new key (both of which I have) and transform the array. Is there an efficient way of doing this?

In PHP, how do you change the key of an array element?

数据库

我有一个形式为key => value的关联数组，其中key是一个数值，但它不是连续的数值。键实际上是一个ID号，值是一个计数。这对于大多数情况都很好，但是我想要一个函数，它可以获取数组的人类可读的名称，并使用该名称作为键，而不需要更改值。我没有看到这样做的函数，但我假设我需要提供旧的密钥和新的密钥(这两个都是我拥有的)并转换数组。有没有一种有效的方法来做到这一点？

问在PHP中，如何更改数组元素的键？
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