Nested classes are classes that are declared as members of other classes or scopes. Nesting classes is one way to better organize your code. For example, say you have a non-nested class (also known as ...

为什么我写java程序时，明明一点语法错误都没有，但是编译时总会出这个错误：non-static variable this cannot be referenced from a static context？ 害得我要在每一个变量、函数、类前加上static才能解决，为什么会这样呢？有没有什么好的解决方法？