我有以下数组：
$inputArray = Array(
[0] => stdClass Object (
[id] => 8
)
[1] => stdClass Object (
[id] => 7
)
[2] => stdClass Object (
[id] => 5
)
)
$sortingArray = [5,8,1]
我正在寻找一种通过ID“值映射”对输入数组进行排序的有效方法。预期的输出应为$ inputArray重新排序，以便第3个项目位于第一个，第一个项目为第2个，依此类推。
谢谢！
答案 0 :(得分：2)
您可以使用webpackHotDevClient.js:138 C:/Users/benja/Documents/Udacity/Project-7/react-map/node_modules/object-assign/index.js
There are multiple modules with names that only differ in casing.
This can lead to unexpected behavior when compiling on a filesystem with other case-semantic.
Use equal casing. Compare these module identifiers:
* C:\Users\benja\Documents\Udacity\Project-7\react-map\node_modules\object-assign\index.js
Used by 1 module(s), i. e.
C:\Users\benja\Documents\Udacity\Project-7\react-map\node_modules\react-scripts\config\polyfills.js
* C:\Users\benja\documents\udacity\project-7\react-map\node_modules\object-assign\index.js
Used by 3 module(s), i. e.
C:\Users\benja\documents\udacity\project-7\react-map\node_modules\react\cjs\react.development.js
printWarnings @ webpackHotDevClient.js:138
handleWarnings @ webpackHotDevClient.js:155
./node_modules/react-dev-utils/webpackHotDevClient.js.connection.onmessage @ webpackHotDevClient.js:208
./node_modules/sockjs-client/lib/event/eventtarget.js.EventTarget.dispatchEvent @ eventtarget.js:51
(anonymous) @ main.js:278
./node_modules/sockjs-client/lib/main.js.SockJS._transportMessage @ main.js:276
./node_modules/sockjs-client/lib/event/emitter.js.EventEmitter.emit @ emitter.js:50
WebSocketTransport.ws.onmessage @ websocket.js:35
webpackHotDevClient.js:138 (webpack)/buildin/global.js
There are multiple modules with names that only differ in casing.
This can lead to unexpected behavior when compiling on a filesystem with other case-semantic.
Use equal casing. Compare these module identifiers:
* C:\Users\benja\Documents\Udacity\Project-7\react-map\node_modules\webpack\buildin\global.js
Used by 23 module(s), i. e.
C:\Users\benja\Documents\Udacity\Project-7\react-map\node_modules\sockjs-client\lib\entry.js
* C:\Users\benja\documents\udacity\project-7\react-map\node_modules\webpack\buildin\global.js
Used by 2 module(s), i. e.
C:\Users\benja\documents\udacity\project-7\react-map\node_modules\symbol-observable\es\index.js
printWarnings @ webpackHotDevClient.js:138
handleWarnings @ webpackHotDevClient.js:155
./node_modules/react-dev-utils/webpackHotDevClient.js.connection.onmessage @ webpackHotDevClient.js:208
./node_modules/sockjs-client/lib/event/eventtarget.js.EventTarget.dispatchEvent @ eventtarget.js:51
(anonymous) @ main.js:278
./node_modules/sockjs-client/lib/main.js.SockJS._transportMessage @ main.js:276
./node_modules/sockjs-client/lib/event/emitter.js.EventEmitter.emit @ emitter.js:50
WebSocketTransport.ws.onmessage @ websocket.js:35
webpackHotDevClient.js:138 (webpack)/buildin/module.js
There are multiple modules with names that only differ in casing.
This can lead to unexpected behavior when compiling on a filesystem with other case-semantic.
Use equal casing. Compare these module identifiers:
* C:\Users\benja\Documents\Udacity\Project-7\react-map\node_modules\webpack\buildin\module.js
Used by 3 module(s), i. e.
C:\Users\benja\Documents\Udacity\Project-7\react-map\node_modules\node-libs-browser\node_modules\punycode\punycode.js
* C:\Users\benja\documents\udacity\project-7\react-map\node_modules\webpack\buildin\module.js
Used by 2 module(s), i. e.
C:\Users\benja\documents\udacity\project-7\react-map\node_modules\lodash\isBuffer.js来创建一个临时数组。这将翻转数组，这意味着值将是关键。
使用array_flip对数组进行排序。
usort这将导致：
$tempArr = array_flip( $sortingArray );
usort($inputArray, function($a, $b) use ( $tempArr ) {
$tempA = isset( $tempArr[ $a->id ] ) ? $tempArr[ $a->id ] : 999999; //If id does not exist on $sortingArray. Use 999999 as an index
$tempB = isset( $tempArr[ $b->id ] ) ? $tempArr[ $b->id ] : 999999;
return $tempA - $tempB;
});
echo "<pre>";
print_r( $inputArray );
echo "</pre>";
答案 1 :(得分：1)
我在这里使用了几件事，主要是我将排序数组用作array_replace()的目标，并使用array_column()来索引对象（这需要PHP 7.0 +用于处理对象）...
$input = array_column($inputArray, null, "id");
$sort = array_fill_keys($sortingArray, null);
$output = array_filter(array_replace($sort, $input));
array_filter()将删除不在输入数组中但在排序数组中的所有元素。使用array_fill_keys()代替array_flip()，以便我可以设置一个空值，使过滤器可以工作。
答案 2 :(得分：0)
首先，如果输入数组是MySQL查询的结果集，则应该通过ORDER BY子句对数据进行排序。 FIELD()是一项出色的工作工具，有些奇怪，您需要颠倒排序逻辑并在函数后写上DESC。
资源：https://www.electrictoolbox.com/mysql-order-specific-field-values/（向下滚动到“陷阱”）
SQL Fiddle演示：http://sqlfiddle.com/#!9/6b996f/1
除此之外，我还将利用php7 +优点提供Nigel和Eddie解决方案的两个改进版本。您选择实施哪一个将与：
id值的元素“生存”该过程$array = [
(object)['id' => 8],
(object)['id' => 7],
(object)['id' => 5]
];
$order = [5, 8, 1]; // custom sort order
$order = array_flip($order); // restructure for easy lookup with isset()
$order[''] = max(array_column($array, 'id')) + 1; // append value higher than max for outlying ids
usort($array, function($a, $b) use ($order) {
return ($order[$a->id] ?? $order['']) <=> ($order[$b->id] ?? $order['']);
});
var_export($array);
*请注意，我可以将$outlier作为第二个use参数传递到自定义函数范围中，并用$order['']替换所有$outlier变量，但是我选择了将异常数据添加到查找数组中。
*我在自定义函数中使用了括号，不仅是为了提高可读性，而且是为了确保按预期执行评估-在没有括号分组的情况下，我实际上没有费心检查评估是否相同。
（PHP Demo）
$array = [
(object)['id' => 8],
(object)['id' => 7],
(object)['id' => 5]
];
$order = [5, 8, 1];
$order = array_flip($order); // flip for future key comparisons
$keyed = array_column($array, null, 'id'); // declare id values as new keys
$filtered_order = array_intersect_key($order, $keyed); // remove unwanted order keys
$replaced = array_replace($filtered_order, $keyed); // apply objects to output array
var_export(array_values($replaced)); // re-index the output (if desired)
*请注意，这不会生成null值的超大数组，也不会删除“假”值。
*我将再次声明，如果在输入数组中存在重复的array_column()值，则使用id会损坏数据。