什么是接口

泛型用来指定只能放某一类型的元素，不能放其它类型的元素

泛型的概念

//类的实例化是通过new关键字来完成的

//访问控制符：public,private(私有，内部可以访问，外部访问不到),protected(受保护的，内部和子类可以访问，外部访问不到)

//构造函数只能被调用一次，new实例化的时候调用，只会被调用一次，外部无法访问

class Person {

    constructor(public name:string){

        console.log('haha')

    }

    eat(){

        console.log('im eating')

    }

}

var p1 = new Person("batman")

// p1.eat();

var p2 = new Person("superman")

// p2.eat()

//类的继承extends

class Employee extends Person {

    code: String;

     work() {

        super.eat();

        this.doWork();

    }

    private doWork(){

        console.log('im working')  

    }

}

var e1 = new Employee("name")

e1.work()

//类的super关键子，用来调父类的构造函数

for...in

forEach只遍历数组元素，循环不能被打断；

for...in 数组属性和元素下标，所以遍历数据的时候可能会有坑；

// let arr = [1,2,3,4]

// arr.name = ''lili

for...of 遍历数组元素，循环可以被打断，可用于任何对象上（map, set string....）

//针对数组的析构表达式

let array1 = [1,2,3,4];

let [number1,number2] = array1;

//let [，，number1,number2] = array1;

//let [number1,number2,...others] = array1;

console.log(number1);

console.log(number2);

function doSomething([number1,number2,...others]){

    console,log(number1)

    console.log(number2)

    console.log(others)

}

doSomething(array1)

//析构表达式大括号的变量要跟对象里面的名字相等，除非用冒号给昵称

function getStock(){

    return {

        code : 'IBM',

        price : 100,

        price66: {

            price1:200,

            price2:400

        },

        aaa: 'xixi'

    }

}

var {code:codex,price,price66:{price2}} =  getStock();

console.log(codex);

console.log(price)

console.log(price2)

//destructuring析构表达式：通过表达式将对象或数组拆解成任意数量的变量

generator函数：

控制函数的执行过程，手工暂停和恢复代码执行

//Rest and Spread操作符：用来声明任意数量的方法参数

function func1(...args) {

    args.forEach(function(arg){

        console.log(arg)

    })

}

func1(1,2,3,4)

func1(7,8,9,10)

function fun2(a,b,c){

    console.log(a);

    console.log(b);

    console.log(c);

}

var args = [1,2]

func2(...args);

var args2 = [7,8,9,10,11]

func2(...args2)

可选参数必须写在必选参数后边

let myname :string = 'lilian'

function test(a:string,b:string,c:string= 'jojo'){

    console.log(a)

    console.log(b)

    console.log(c)

}

test('xxx','yyy','zzz')

test('xxx','yyy')

var myname:string = 'vivian'

//类型检查会提示

myname = '' 

//ts自动类型推断机制，除非设置为any

var alias:any = 'xixi';

var age:number = 13;

var man:boolean = true;

//为函数的参数和返回值定义类型

function test(name:string) :string {

    return ''

}

class Person {

    name: string;

    age: number;

}

var zhangsan: Person = new Person();

zhangsan.name = 'cician'

zhangsan.age = 18

字符串模版

let myName = 'vivian'

let getAge = ()=> 18

console.log(`hello${myName}`)

console.log(`hello${getAge()}`)

function test(template,name,age) {

console.log(template);

console.log(name)

console.log(age)

}

test `hello my name is ${myName}, i'm ${getAge()}`