学习TypeScript 接口

TypeScript 接口定义

interface interface_name {
}

实例

interface IPerson { 
    firstName:string, 
    lastName:string, 
    sayHi: ()=>string 
} 
 
var customer:IPerson = { 
    firstName:"Tom",
    lastName:"Hanks", 
    sayHi: ():string =>{return "Hi there"} 
} 
 
console.log("Customer 对象 ") 
console.log(customer.firstName) 
console.log(customer.lastName) 
console.log(customer.sayHi())  
 
var employee:IPerson = { 
    firstName:"Jim",
    lastName:"Blakes", 
    sayHi: ():string =>{return "Hello!!!"} 
} 
 
console.log("Employee  对象 ") 
console.log(employee.firstName) 
console.log(employee.lastName)

联合类型和接口

interface RunOptions { 
    program:string; 
    commandline:string[]|string|(()=>string); 
} 
 
// commandline 是字符串
var options:RunOptions = {program:"test1",commandline:"Hello"}; 
console.log(options.commandline)  
 
// commandline 是字符串数组
options = {program:"test1",commandline:["Hello","World"]}; 
console.log(options.commandline[0]); 
console.log(options.commandline[1]);  
 
// commandline 是一个函数表达式
options = {program:"test1",commandline:()=>{return "**Hello World**";}}; 
 
var fn:any = options.commandline; 
console.log(fn());

接口和数组

interface namelist { 
   [index:number]:string 
} 
 
var list2:namelist = ["John",1,"Bran"] // 错误元素 1 不是 string 类型
interface ages { 
   [index:string]:number 
} 
 
var agelist:ages; 
agelist["John"] = 15   // 正确 
agelist[2] = "nine"   // 错误

接口继承

Child_interface_name extends super_interface_name
多接口继承语法格式：
Child_interface_name extends super_interface1_name, super_interface2_name,…,super_interfaceN_name

单继承实例

interface Person { 
   age:number 
} 
 
interface Musician extends Person { 
   instrument:string 
} 
 
var drummer = <Musician>{}; 
drummer.age = 27 
drummer.instrument = "Drums" 
console.log("年龄:  "+drummer.age)
console.log("喜欢的乐器:  "+drummer.instrument)

多继承实例

interface IParent1 { 
    v1:number 
} 
 
interface IParent2 { 
    v2:number 
} 
 
interface Child extends IParent1, IParent2 { } 
var Iobj:Child = { v1:12, v2:23} 
console.log("value 1: "+Iobj.v1+" value 2: "+Iobj.v2)