Object-oriented
- Define a class
class 类名{
名称:数据类型；
constructor(参数:数据类型){
} // 构造函数
方法名():返回值类型{
}
}
Omit the public keyword
, trigger when the constructor is instantiated
- Attribute modifier
用来修饰类里面的属性和方法
public
公有 类里面，类外面，子类，都可以访问
protected
保护 类里面，子类，可以访问
provite
私有 只有在 类里面 可以访问
- The inherited method
super is to initialize the constructor of the parent class, this is the same as es2015
class 子类名 extends 父类名{
constructor(参数名a:数据类型){
super(参数名a)；
}
}
- implements keyword
class C implements A{
//。。。
}
The implements keyword treats class A as an interface, which means that class C must implement all methods defined in class A, regardless of whether these methods are implemented in class A by default. At the same time, there is no need to define the super method in class C.
-
Static properties
在属性名前加一个 static 关键字
调用方法
父类名.属性名
- Static method static
add a static keyword before the method is a static method,
static method can call static properties
class 类名{
static 静态方法名(){
}
}
调用: 父类.方法名
- Polymorphism (belongs to inheritance)
The parent class defines a method not to implement it, and let the subclasses that inherit it implement it. Each subclass has a different performance
父类
class 父类名{
属性名a:数据类型；
constructor(参数a:数据类型){
}
方法名a(){
}
}
子类
class 父类名 extends 子类{
constructor(参数a:数据类型){
super(属性名a)
}
父类方法名a(){
内容}
}
- abstract
-
Use the abstract keyword to define abstract classes and abstract methods. The abstract methods in abstract classes do not contain concrete implementations and must be implemented in derived classes
-
Abstract methods can only be placed in abstract classes
-
Abstract classes and abstract methods are used to define standards. The parent class requires that its subclasses must contain a method of the parent class
-
Abstract classes mainly provide base classes for subclasses and cannot be instantiated directly
抽象类
abstract class 父类名(){
}
抽象方法
abstract class 父类名(){
abstract 抽象方法名():返回值类型;
}