CODE - 执行函数后,对象的内容会更改 [英] CODE - The content of an object is changed after executing a function
问题描述
问题是 $ oldpop
的内容在执行函数 func
后会发生神奇的变化, func
是 $ matepop
。内部 func
, $ oldpop
不使用(我添加了注释行以显示地方 - MAIN.PHP 的代码段)。下面我只提供代码的一些主要部分。也许有人可以提出问题的原因?
The problem is that the content of $oldpop
get magically changed after executing the function func
, whereas the input of func
is $matepop
. Inside func
, $oldpop
is not used (I added the comment line to show the place - see the end of the code snippet of MAIN.PHP). Below I provide just some principal parts of the code. Maybe, someone could suggest the reason of the problem?
我应该提到我不使用静态变量。
I should mention I don't use static variables.
档案MAIN.PHP
include_once 'func.php';
include_once 'select.php';
class Individual {
private $genes;
private $rank;
public function __construct() {
$this->genes = array();
$this->rank = 0;
}
public function setRank($val){
$this->rank = $val;
}
public function setGene($i,$val){
$this->genes[$i] = $val;
}
}
class Population {
private $ind;
public function __construct()
{
$this->ind = array();
}
public function addIndividual(Individual $ind)
{
$this->ind[] = $ind;
}
public function getIndividual($i){
return $this->ind[$i];
}
}
$oldpop = new Population();
for($i=0; $i<$popsize; $i++) {
$oldpop->addIndividual(new Individual());
}
$oldpop = func($oldpop,$popsize);
for ($i = 0; $i < $gener; $i++)
{
$matepop = new Population();
$matepop = nselect($matepop,$oldpop,$popsize);
// !!! Here the $oldpop content is correct (original)
$matepop = func($matepop,$popsize);
// !!!! Here the original content of $oldpop is magically changed
}
文件SELECT.PHP
function nselect($matepop,$oldpop,$popsize) {
$select = array();
//...
$select[] = $oldpop->getIndividual($i);
//...
for ($i=0; $i < $popsize; $i++) {
$matepop->addIndividual($select[$i]);
}
return $matepop;
}
文件FUNC.PHP b
$ b
File FUNC.PHP
function func($pop,$popsize) {
//...
$pop->getIndividual($i)->setRank($val);
//...
return $pop;
}
推荐答案
PHP对象变量不包含对象的完整副本; 这意味着当你使用
$select[] = $oldpop->getIndividual($i);
在代码中,您没有创建对象的新副本 $ i
;您只需将对象 $ i
的引用复制到数组 $ select
中。这意味着 $ oldpop
和 $ matepop
都包含对其中的相同 $ ind
数组。然后,当您以后使用
in your code, you didn't make a new copy of the object $i
; you simply copied the reference to the object $i
into the array $select
. This means that both $oldpop
and $matepop
contain references to the same objects in their $ind
arrays. Then, when you later used
$pop->getIndividual($i)->setRank($val);
设置每个个人
在 $ matepop
中的类对象,它们也更改为 $ oldpop
。
to set the rank of each Individual
-class object in $matepop
, they also changed for $oldpop
.
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