PHP object-oriented classes and instantiated objects
This article mainly introduces PHP object-oriented classes and instantiated objects, which has a certain reference value. Now I share it with everyone. Friends in need can refer to it
Class
Declaration
[修饰符] class 类名
{
[属性]
[方法]
}Notes:
1) The class name follows the camel case naming convention that starts with uppercase
private 私有
protected 保护
public 公共
var 被视为public (不建议使用)
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Access permission
private 私有 protected 保护 public 公共 var 被视为public (不建议使用)
// 1.声明类
class Dog
{
// 2.定义属性
public $name = '旺财';
public $sex = null;
// 3.定义方法
public function bark()
{
echo '汪汪~';
}
}
// 4.实例化
$d1 = new Dog();Copy after login
// 1.声明类
class Dog
{
// 2.定义属性
public $name = '旺财';
public $sex = null;
// 3.定义方法
public function bark()
{
echo '汪汪~';
}
}
// 4.实例化
$d1 = new Dog();Instantiated objectInvocation of properties and methodsUse
-> , to access non-static properties | methods.
Example
// 声明类
class Dog
{
// 定义属性
public $name = '旺财';
public $sex = null;
// 定义方法
public function bark()
{
echo '汪汪~';
}
}
// 实例化
$d1 = new Dog();
// 使用属性和方法
echo $d1 -> name;
echo '<br/>';
echo $d1 -> bark();$this .
$this represents the object being used.
Example:
// 声明类
class Dog
{
// 定义属性
public $name = '旺财';
public $sex = null;
public function intruduce()
{
echo '我的名字是'.$this->name;
}
}Simple type, both sides of the assignment, mutually independent.
composite type, the identifier of the object is stored in the transfer assignment, so the changes are consistent .
Simple type example:
$a = 'abc'; // 传递赋值 $b = $a; // 更改a的值 $a = 'qq'; var_dump($a); // qq var_dump($b); // abc
Composite type example:
class MyClass
{
public $str = 'abc';
}
// $a 存的是对象的标识符
$a = new MyClass();
// 传递赋值 相当于把标识符赋值给了$b
$b = $a;
var_dump($a); // abc
var_dump($b); // abc
// 更改a对象str属性的值
$a -> str ='111';
// $a和$b存的都是标识符
var_dump($a); // 111
var_dump($b); // 111
// 更改a本身的值
$a = 123;
var_dump($a); // 123
var_dump($b); // 111 对象标识符Example:
$a = 'abc'; // 引用赋值 $c = &$a; var_dump($a); // qq var_dump($c); // qq
php basic object-oriented concepts
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