题解 | #双向绑定#

    for (const key in person) {
        let oldVal = person[key];
        Object.defineProperty(person, key, {
            configurable: true,
            get() {
                return oldVal;
            },
            set(val) {
                oldVal = val;
                _render(ul);
            }
        })
    }

    inp.oninput = function () {
        person.weight = this.value;
    }