请问老师我下面的代码怎么回陷入死循环，是哪里错了

// 有length和索引属性的对象
        const obj = {
            0: "Elisha",
            1: 18,
            length: 2
        };

        obj[Symbol.iterator] = () => {
            let index = 0;
            return {
                next() {
                    let value, done;
                    if (index < obj.length) {
                        value = obj[index];
                        done = false;
                    } else {
                        value: undefined;
                        done: true;
                    }

                    index++;

                    return {
                        value,
                        done
                    };
                }
            };
        };

        for (const item of obj) {
            console.log(item);
        }