继承

abstract class Animal {
    name: string;

    constructor(name: string) {
        this.name = name;
    }

    abstract sayHello(): void;
}



class Dog extends Animal {
    sayHello() {
        console.log('汪汪汪汪！');
    }
}

class Cat extends Animal {
    sayHello() {
        console.log('喵喵喵喵！');
    }
}

const dog = new Dog('旺财');
dog.sayHello();

const smallCat = new Cat('小喵');
smallCat.sayHello();

ts 的 getter setter

(function () {
    class Person {

        private _name: string;
        private _age: number;

        constructor(name: string, age: number) {
            this._name = name;
            this._age = age;
        }

        get name() {
            return this._name;
        }

        set name(value) {
            console.log('set name()执行了！！');
            this._name = value;
        }

        get age() {
            return this._age;
        }

        set age(value) {
            console.log('set age()执行了！！');
            if (value >= 0) {
                this._age = value
            } else {
                console.log('非法的年龄')
            }
        }
    }

    const per = new Person('name', 18);



    per.name = '猪八戒';
    per.age = -33;

    console.log(per);
})();