Typescript Study Notes (c): Class

Class

In typescript, a structure similar to C #, where multiple classes can exist in a file, and the filenames can be arbitrarily taken, let's look at a simple example of a class.

1 class Person {2 private name:string;3 private age:number;4 5 Public Constructor (name:string, Age:number) {6          This. Name =name;7          This. Age =Age ;8     }9 Ten Public talk () { OneAlert ("Hi, my name is" + This. Name + ", I am" + This. age.tostring () + "!"); A     } - } -  the functionrun () { -     varP:person =NewPerson ("Li Lei", 18); - P.talk (); - } +  -Run ();

The classes in typescript need to be aware of the following points:

• Class without the access control, all classes are globally publicly accessible;
• If the properties and methods of the class are not added to the access control Fuzeme is considered public;
• 1.3 Start to support protected Access, only public and private before 1.3;
• Constructors are not class names but constructor;
• Access to the class's member variables and functions are required to add the this keyword;

Inheritance of Classes

In typescript, how to implement class inheritance, see the following example:

1 class Person2 {3 private name:string;4 private age:number;5 6 Constructor (name:string, Age:number)7     {8          This. Name =name;9          This. Age =Age ;Ten     } One  A Talk () -     { -Alert ("Hi, my name is" + This. Name + ", I am" + This. age.tostring () + "!"); the     } - } -  - class Student extends person + { - private school:string; +  A Constructor (name:string, Age:number, school:string) at     { - Super (name, age); -          This. School =School; -     } -  - Talk () in     { - Super.talk (); toAlert ("and I ' m in" + This. School + "!"); +     } - } the  * functionRun () $ {Panax Notoginseng     varP:person =NewStudent ("Li Lei", "中文版 School")); - P.talk (); the } +  ARun ();

The inheritance of classes requires attention to the following points:

• Inheritance using extends keywords;
• Call the parent using the Super keyword;
• Overriding the parent method does not require the Override keyword to define the same method directly;
• A parent variable can be called to a child's method, conforming to the concept of polymorphism;

Getter/setter Package

In typescript we can encapsulate a member variable in getter and setter, as follows:

1 class Person2 {3 private _name:string;4 5 Constructor (name:string)6     {7          This. _name =name;8     }9 TenSet Name (value:string) { This. _name =value;} OneGet Name () {return  This. _name;} A  - Talk () -     { theAlert ("Hi, my name is" + This. Name + "!"); -     } - } -  + functionRun () - { +     varP:person =NewPerson (NULL); AP.name = "Li Lie"; at P.talk (); - } -  -Run ();

static Data and methods

In typescript, static variables and static functions can be defined using static, and we take the Singleton class as an example to see:

1 class Person2 {3 private static _instance:person;4 5 static getinstance ():P Erson6     {7         if( This. _instance = =NULL)8         {9              This. _instance =NewPerson ();Ten         } One         return  This. _instance; A     } -  - Talk () the     { -Alert ("Hi, my name is Li lie!"); -     } - } +  - functionRun () + { A person.getinstance (). talk (); at } -  -Run ();

Typescript Study Notes (c): Class