TypeScript-接口和类型别名异同

1.都可以描述属性或方法

type MyType = {
    
    name:string;
    say():void;
}
interface MyInterface {
    
    name:string;
    say():void;
}

2.都允许拓展

interface MyInterface {
    
    name:string;
    say():void;
}
interface MyInterface2 extends MyInterface{
    
    age:number;
}
let value:MyInterface2 = {
    
    name:'lnj',
    age:18,
    say():void{
    

    }
}

type MyType = {
    
    name:string;
    say():void;
}
type MyType2 = MyType & {
    
    age:number;
}
let value:MyType2 = {
    
    name:'lnj',
    age: 18,
    say():void{
    

    }
}

3.type 可以声明基本类型别名，联合类型，元组等类型, interface不能

type MyType1 = boolean;
type MyType2 = string | number;
type MyType3 = [string, boolean, number];

4.type不会自动合并

interface MyInterface {
    
    name:string
}
interface MyInterface {
    
    age:number
}
let value:MyInterface  ={
    
    name:'lnj',
    age:18
}

type MyType = {
    
    name:string
}
type MyType = {
    
    age:number
}