1. 先看代码 {#1.-%E5%85%88%E7%9C%8B%E4%BB%A3%E7%A0%81}

2. 发现问题 {#2.-%E5%8F%91%E7%8E%B0%E9%97%AE%E9%A2%98}

3. 分析问题 {#3.-%E5%88%86%E6%9E%90%E9%97%AE%E9%A2%98}

4. 解决问题 {#4.-%E8%A7%A3%E5%86%B3%E9%97%AE%E9%A2%98}