在下面的代码中,我无法理解为什么变量$service_category_tree
会自行更改。不知何故,subscription_tree
改变了参数变量,尽管它没有通过引用传递。
$service_category_tree = $this->service_category_model->with_request_forms();
foreach ($this->view_data['users'] as &$user) {
echo md5(serialize($service_category_tree))."<br>"; // To check if the variable is changed.
$user->service_categories = $this->merchant_model->subscription_tree($user->id, $service_category_tree);
}
如您所见,MD5语句的输出显示变量已更改:
10066a31bb6e191fbb94b8dc61fd6e55
10066a31bb6e191fbb94b8dc61fd6e55
fd1e22aa74c048e88751c85528d23254
752e0cef4357d7a33e47b90ef207d396
8b5b6ea856080bf32b9bfecc4e43a3f6
8b5b6ea856080bf32b9bfecc4e43a3f6
8b5b6ea856080bf32b9bfecc4e43a3f6
3f3e7619e59e3776c395065e4278c3f8
3f3e7619e59e3776c395065e4278c3f8
dbfebae62d65bd04ce4ce74f2046f90e
34498709256b34ce4d843c1f735c4c6a
方法subscription_tree
在第二个参数上没有&符号,如下面的代码所示。
function subscription_tree($merchant_id, $tree_array = NULL){
if($tree_array === NULL){
$this->load->model('service_category_model');
$tree_array = $this->service_category_model->with_request_forms();
}
if(is_array($tree_array) && count($tree_array)){
$my_request_forms = $this->request_forms($merchant_id)->result();
$my_service_categories = $this->service_categories($merchant_id)->result();
foreach ($tree_array as &$sc) {
// Indicate subscribed service categories
$sc->subscribed = FALSE;
if(is_array($my_service_categories) && count($my_service_categories)) {
foreach ($my_service_categories as $my_sc_key => $my_sc) {
if($my_sc->id == $sc->id){
$sc->subscribed = TRUE;
unset($my_service_categories[$my_sc_key]);
}
}
}
// Indicate subscribed request forms
if(is_array($sc->request_forms) && count($sc->request_forms)) {
foreach ($sc->request_forms as &$rf) {
$rf->subscribed = FALSE;
if(count($my_request_forms)) {
foreach($my_request_forms as $mrf_key => $my_request_form){
if ( $my_request_form->id == $rf->id ) {
$rf->subscribed = TRUE;
unset($my_request_forms[$mrf_key]);
break;
}
}
}
}
}
}
}
return $tree_array;
}
答案 0 :(得分:2)
在PHP中,对象总是通过引用传递:
如此行
foreach ($tree_array as &$sc) {
// Indicate subscribed service categories
$sc->subscribed = FALSE;
可以更改$tree_array
对象,这是对$service_category_tree
您还可以制作阵列的深层复制:
$new_tree = array();
foreach ($service_category_tree as $k => $v) {
$new_tree[$k] = clone $v;
}
并将其传递给该函数。或者在函数中做一个深层复制......
的更多信息