函数uasort在PHP 5.5和PHP 7.0中的不同行为 [英] The different behavior of the function uasort in PHP 5.5 and PHP 7.0
问题描述
在将PHP版本从5.5更改为7.0之后,我遇到了Magento 1.8的奇怪行为.
这种奇怪的行为是由于工作功能uasort
的更改所致.
I encountered a strange behavior of Magento 1.8 after changing php version from 5.5 to 7.0.
This strange behavior is due to a change in the work function uasort
.
源代码:
<?php
$arr = [
"nominal" => [
"before" => ["subtotal", "grand_total"],
"after" => [],
"_code" => "nominal"
],
"subtotal" => [
"after" => ["nominal"],
"before" => ["grand_total", "shipping", "freeshipping", "tax_subtotal", "discount", "tax", "weee"],
"_code" => "subtotal"
],
"shipping" => [
"after" => ["subtotal", "freeshipping", "tax_subtotal", "nominal", "weee"],
"before" => ["grand_total", "discount", "tax_shipping", "tax"],
"_code" => "shipping"
],
"grand_total" => [
"after" => ["subtotal", "nominal", "shipping", "freeshipping", "tax_subtotal", "discount", "tax"],
"before" => [],
"_code" => "grand_total"
],
"msrp" => [
"before" => [],
"after" => [],
"_code" => "msrp"
],
"freeshipping" => [
"after" => ["subtotal", "nominal"],
"before" => ["tax_subtotal", "shipping", "grand_total", "tax", "discount"],
"_code" => "freeshipping"
],
"discount" => [
"after" => ["subtotal", "shipping", "nominal", "freeshipping", "tax_subtotal", "tax_shipping", "weee"],
"before" => ["grand_total", "tax"],
"_code" => "discount"
],
"tax_subtotal" => [
"after" => ["0" => "freeshipping", "1" => "subtotal", "3" => "nominal"],
"before" => ["tax", "discount", "shipping", "grand_total", "tax_shipping", "weee"],
"_code" => "tax_subtotal"
],
"tax_shipping" => [
"after" => ["shipping", "tax_subtotal", "subtotal", "freeshipping", "nominal"],
"before" => ["tax", "discount", "grand_total"],
"_code" => "tax_shipping"
],
"tax" => [
"after" => ["subtotal", "shipping", "discount", "tax_subtotal", "freeshipping", "tax_shipping", "nominal", "weee"],
"before" => ["grand_total"],
"_code" => "tax"
],
"weee" => [
"after" => ["subtotal", "tax_subtotal", "nominal", "freeshipping"],
"before" => ["shipping", "tax", "discount", "grand_total", "tax_shipping"],
"_code" => "weee"
]
];
function _compareTotals($a, $b)
{
$aCode = $a['_code'];
$bCode = $b['_code'];
if (in_array($aCode, $b['after']) || in_array($bCode, $a['before'])) {
$res = -1;
} elseif (in_array($bCode, $a['after']) || in_array($aCode, $b['before'])) {
$res = 1;
} else {
$res = 0;
}
echo sprintf("%s <> %s: %s", $aCode, $bCode, $res) . "\n";
return $res;
}
uasort($arr, '_compareTotals');
var_dump(array_keys($arr));
在php 5.5中,结果是:
In php 5.5 result is:
freeshipping <> subtotal: 1
freeshipping <> shipping: -1
weee <> freeshipping: 1
tax <> freeshipping: 1
tax_shipping <> freeshipping: 1
tax_subtotal <> freeshipping: 1
discount <> freeshipping: 1
nominal <> freeshipping: -1
freeshipping <> grand_total: -1
msrp <> freeshipping: 0
subtotal <> msrp: 0
nominal <> subtotal: -1
tax_subtotal <> shipping: -1
weee <> tax_subtotal: 1
tax <> tax_subtotal: 1
tax_shipping <> tax_subtotal: 1
grand_total <> tax_subtotal: 1
discount <> tax_subtotal: 1
shipping <> tax_subtotal: 1
grand_total <> discount: 1
grand_total <> shipping: 1
grand_total <> tax_shipping: 1
grand_total <> tax: 1
weee <> grand_total: -1
shipping <> discount: -1
tax <> shipping: 1
tax_shipping <> shipping: 1
weee <> shipping: -1
tax_shipping <> discount: -1
tax <> tax_shipping: 1
discount <> tax_shipping: 1
tax <> discount: 1
array(11) {
[0] =>
string(7) "nominal"
[1] =>
string(8) "subtotal"
[2] =>
string(4) "msrp"
[3] =>
string(12) "freeshipping"
[4] =>
string(12) "tax_subtotal"
[5] =>
string(4) "weee"
[6] =>
string(8) "shipping"
[7] =>
string(12) "tax_shipping"
[8] =>
string(8) "discount"
[9] =>
string(3) "tax"
[10] =>
string(11) "grand_total"
}
在php 7.0中,结果是:
In php 7.0 result is:
nominal <> subtotal: -1
subtotal <> shipping: -1
shipping <> grand_total: -1
grand_total <> msrp: 0
msrp <> freeshipping: 0
freeshipping <> discount: -1
discount <> tax_subtotal: 1
msrp <> tax_subtotal: 0
freeshipping <> tax_subtotal: -1
discount <> tax_shipping: 1
freeshipping <> tax_shipping: -1
tax_subtotal <> tax_shipping: -1
discount <> tax: -1
tax <> weee: 1
tax_shipping <> weee: 1
freeshipping <> weee: -1
tax_subtotal <> weee: -1
array(11) {
[0] =>
string(7) "nominal"
[1] =>
string(8) "subtotal"
[2] =>
string(8) "shipping"
[3] =>
string(11) "grand_total"
[4] =>
string(4) "msrp"
[5] =>
string(12) "freeshipping"
[6] =>
string(12) "tax_subtotal"
[7] =>
string(4) "weee"
[8] =>
string(12) "tax_shipping"
[9] =>
string(8) "discount"
[10] =>
string(3) "tax"
}
在PHP5中,grand_total
是最后一个元素,但是在PHP7中-不.
问题与位置msrp
元素的不确定性有关.我在此上找到了研究与php 5相关的主题.
In PHP5 grand_total
is the last element, but in PHP7 - no.
The problem is related to the uncertainty of the location msrp
element. I found a research on this subject associated with php 5.
我通过指示相对位置msrp
解决了这个问题.但是我不知道为什么它可以在php5中工作而不能在php7中工作.这些是新版php的功能还是错误?
I solved this problem by indicating a relative position msrp
. But I wonder why it works in php5 and does not work in php7. These are the features of the new version of php or a bug?
添加#1
问题不仅在于PHP7不知道如何对相等的元素进行排序,例如msrp
和grand_total
.
如果查看项目shipping
和freeshipping
,则会清楚地定义它们,应该更早些. PHP5解决了这个问题,而PHP7不能解决.
The problem not only in that the PHP7 don't knows how to sort equal elements, for example msrp
and grand_total
.
If you look at item shipping
and freeshipping
, then they are clearly defined, who should be earlier. PHP5 solves this problem, and PHP7 not.
推荐答案
从 usort()
文档中:
注意::如果两个成员比较相等,则它们在排序数组中的相对顺序是不确定的.
Note: If two members compare as equal, their relative order in the sorted array is undefined.
这就是您在这里看到的. PHP 7使用了不同的,部分稳定的排序算法,因此根据您的排序功能比较相等的元素现在可能具有不同的顺序.
This is what you're seeing here. PHP 7 uses a different, partially stable sorting algorithm, so elements that compare equal according to your sorting function may now have a different order.
如果您关心相等元素的排序顺序(这不只是一个测试问题),则应在比较函数中使其明确.
If you care about the sorting order of equal elements (and this is not just a testing issue), you should make it explicit in your comparison function.
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