| 作用域 | 当前类 | 同一package | 子孙类 | 其他package |
| public | √ | √ | √ | √ |
| protected | √ | √ | √ | × |
| friendly | √ | √ | × | × |
| private | √ | × | × | × |
不写时默认为friendly
| 作用域 | 当前类 | 同一package | 子孙类 | 其他package |
| public | √ | √ | √ | √ |
| protected | √ | √ | √ | × |
| friendly | √ | √ | × | × |
| private | √ | × | × | × |
不写时默认为friendly
原文：https://www.cnblogs.com/l-W-G/p/8503272.html