SOURCE

let obj = {
    name: 'jerry',
    _name: 'jerry',
    age: 18,
    _age: 18
};
let app = document.getElementById('app');
app.innerHTML = `我叫${obj.name}，今年${obj.age}`
Object.defineProperty(obj, 'age', {
    get: function () {
        console.log('读取mes：' + this._age);
        return this._age;
    },
    set: function (val) {
        this._age = val;
        app.innerHTML = `我叫${this.name}，今年${this.age}`;
        console.log('设置mes：' + val);
    }
})
Object.defineProperty(obj, 'name', {
    get: function () {
        console.log('读取name：' + this._name);
        return this._name;
    },
    set: function (val) {
        this._name = val;
        app.innerHTML = `我叫${this.name}，今年${this.age}`;
        console.log('设置name：' + val);
    }
})

inputName.oninput = function() {
    obj.name = inputName.value
}

inputAge.oninput = function() {
    obj.age = inputAge.value
}

<div id="app"></div>
姓名：<input id="inputName" type="text">
<br>
年龄：<input id="inputAge" type="number">