我会知道在父类和子类之间传递变量的最佳方法是什么，并在整个类中执行更新该类。例如，我有一个父类，它在其中执行的是子类：
class My_Class {
public $data;
public $data2;
public function __construct() {
}
public function output() {
$data['key1'] = 1;
$data['key2'] = 2;
$data2['key1'] = 'a';
$data2['key2'] = 'b';
$child_class = new Child_Class();
$child_class->output();
print_r($this->data); // only contains key1 & key2, I want to get key3 and 4 also
print_r($this->data2);
}
}
class Child_Class extends My_Class {
public function __construct() {
}
public function output() {
$data = parent::$data; // want to get data array but it's empty
$data2 = parent::$data2; // want to get data2 array but it's empty
this->set_data();
}
public function set_data() {
$this->data['key3'] = 3;
$this->data['key4'] = 4;
$this->data['key3'] = 'c';
$this->data['key4'] = 'd';
}
}
$class = new My_class();
$class->output();
目前我在父类中执行子类，因为我需要填充父类的主要数据。此类将基于某个变量执行子类。
将变量从父项继承和赋值到子项以及从子项继承到父项的正确方法是什么？如果我使用依赖注入来检索扩展类中的数据，如何将变量分配给父类？
"你有一个例子吗" - 你去....
<?php
class My_Class {
public $data = array('key1'=>1, 'key2'=>2);
public $data2 = array('key1'=>'a', 'key2'=>'b');
public function output() {
echo "MyClass::output'r'n";
print_r($this->data);
print_r($this->data2);
}
}
class Child_Class extends My_Class {
public function __construct() {
$this->data['key3'] = 3;
$this->data['key4'] = 4;
$this->data2['key3'] = 'c';
$this->data2['key4'] = 'd';
}
public function output() {
echo "Child_Class::output'r'n";
parent::output();
}
}
$class = new Child_Class();
$class->output();
指纹
Child_Class::output
MyClass::output
Array
(
[key1] => 1
[key2] => 2
[key3] => 3
[key4] => 4
)
Array
(
[key1] => a
[key2] => b
[key3] => c
[key4] => d
)
另请参阅：
- https://en.wikipedia.org/wiki/Method_overriding
- http://php.net/manual/en/keyword.parent.php
- 什么是多态性，它的用途是什么，如何使用它？
- https://en.wikipedia.org/wiki/Inheritance_%28object-oriented_programming%29
- https://en.wikipedia.org/wiki/Constructor_%28object-oriented_programming%29
我的问题是一个类型，而不是我写$this->$data $this->data，$符号只需要在每个语句的开头。
我的第二个问题是在访问父类上的变量时省略$this->部分，从而为未与子类共享的父类创建本地范围的变量，应该使用 $this->variable .