二、typescript基础语法

一、条件语句

在这里插入图片描述

二、函数

1、有名函数

	function add(x:number, y:number):number {return x + y;}

2、匿名函数

	let add = function (x:number, y:number):number {return x + y;}

函数可选参数

	function buildName(firstname: string, lastname?:string) {if (lastname) {return firstname + lastname;} else {return firstname;}}let result1 = buildName('wang');let result2 = buildName('wang', 'xiaoming');

函数剩余参数

	function buildName(a: string, ...restparams:string[]) {return a + restparams.join('');}let result1 = buildName('wang');let result2 = buildName('a', 'b', 'c');

3、箭头函数，匿名函数简写，省略了function关键字，可以将箭头函数赋值给变量；

（a, b, ...c）=> {}
let res = （a, b, ...c）=> {}

三、类

class Person {private name:string // 定义私有属性private age:numberconstructor(name:string, age:number){ // 初始化构造函数this.name = name;this.age = age;}public getPersonInfo() { // 公共方法return `my name is ${this.name} and is ${age}岁`;}
}
let xiaoming = new Person('xiaoming', 18);
xiaoming.getPersonInfo()

四、继承

class Employee extends Person {private department:string;constructor(name:string, age:number, department:string) {super(name,age); // 继承this.department = department;}public getEmployeeInfo():string {return this.getPersonInfo() + `and work in ${this.department}`}
}
let person2 = new Employee('xiaoming', 18, 'tech');
person2.getPersonInfo()
person2.getEmployeeInfo()