typescript

完整教程：https://ts.xcatliu.com/

作为JavaScript的升级版，能解决JavaScript弱类型的弱点，建议使用。
特点：各种type，各种提示啊。

效果：

如何使用

// 安装
npm install -g typescript
npm install -g ts-node
// 直接运行
ts-node filename.ts
// 转换为js文件，使用idea时，也可以通过设置自动编译成为js
tsc filename.ts

变量定义

// 普通变量
let strTmp: string = "123";
let isDone: boolean = false;
// 数组
let listAny: Array<any> = [1, 2, 3, "4"];
let listNumber: Array<number> = [1, 2, 3];
// 枚举
enum Color {Red, Green, Blue};
Color.Green;  // 1
Color[1];  // Green

函数

let add = function (left: number, right: number): number {
    return left + right;
};
console.log(add(1, 2));

类

// 类：封装方法和数据--------------
class Shape {
    name: string;
    area: number;
    color: string;
    constructor(name: string, width: number, height: number) {
        this.area = width * height;
        this.color = "pink";
    };
    shoutout() {
        return "I'm " + this.color + " " + this.name + " with an area of " + this.area + " cm squared.";
    }
}
let square = new Shape("square", 30, 30);
console.log(square.shoutout());
// 类的继承------------------
class Shape3D extends Shape {
    volume: number;
    constructor(public name: string, width: number, height: number, length: number) {
        super(name, width, height);
        this.volume = length * this.area;
    };
    shoutout() {
        return "I'm " + this.name + " with a volume of " + this.volume + " cm cube.";
    }
    superShout() {
        return super.shoutout();
    }
}
var cube = new Shape3D("cube", 30, 30, 30);
console.log(cube.shoutout());
console.log(cube.superShout());
// 箭头函数：可以自动修改this指向，settimeout里面的this默认为windows------------
class Shape1 {
    name: string = "rectangle";
    popup() {
        console.log('This inside popup(): ' + this.name);
        setTimeout(() => {
            console.log('This inside setTimeout(): ' + this.name);
            console.log("I'm a " + this.name + "!");
        }, 1);
    }
};
new Shape1().popup();

这短短的一生我们最终都会失去，不放大胆一点，爱一个人、攀一座山、追一个梦！