Why Exception class is checked as its child class RuntimeException is unchecked in Java?

Question

在Exception层次结构中，RuntimeException是未经检查的Exception的子类，但是如果我们使用Exception，则将其视为已检查的Exception为何？

Answer 1

From the Oracle Java documentation :

Runtime exceptions can occur anywhere in a program, and in a typical one they can be very numerous. Having to add runtime exceptions in every method declaration would reduce a program's clarity. Thus, the compiler does not require that you catch or specify runtime exceptions (although you can).

So they added RuntimeExceptions to deal with common run-time problems, without the hassle of catching-or-throwing every single time.