TypeScript声明合并的实现

interface TestInterface {
    name:string;
}
interface TestInterface {
    age:number;
}
//相当于下面
interface TestInterface {
    name:string;
    age:number;
}
class Person implements TestInterface{
    name:string;
    age:number;
}

interface TestInterface {
    name:string;
}
interface TestInterface {
    name:number;//报错
}

interface TestInterface {
    getValue(value:number):number;
}
interface TestInterface {
    getValue(value:string):number;
}
let obj:TestInterface = {
    getValue(value:any):number{
        if(typeof value === 'string'){
            return value.length;
        }else{
            return value.toFixed();
        }
    }
}
console.log(obj.getValue("abcdef"));
console.log(obj.getValue(3.14));

namespace Validation{
    export let name:string = 'lnj';
}
namespace Validation{
    export let age:number = 18;
}
console.log(Validation.name);
console.log(Validation.age);

namespace Validation{
    export let name:string = 'lnj';
    export let say = ()=> "abc";
}
namespace Validation{
    export let name:string = 'zs';//报错
    export let say = ()=> "abc";//报错
}

namespace Validation{
    let name:string = 'lnj';//输出name = 获取不到name
    //  export let name:string = 'lnj'; 输出name =lnj
    
}
namespace Validation{
    export let say = ()=> {
        console.log(`name = ${name}`);
    };
}
Validation.say();

class Person {
    say():void{
        console.log('hello world');
    }
}
namespace Person{
    export const hi = ():void=>{
        console.log('hi');
    }
}
console.dir(Person);

function getCounter() {
    getCounter.count++;
    console.log(getCounter.count);
}
namespace getCounter{
    export let count:number = 0;
}

enum Gender {
    Male,
    Female
}
namespace Gender{
    export const Yao:number = 666;
}
console.log(Gender);