What is method coverage?
Method overwriting is also called overwriting. Overwriting means that the subclass redefines the method of the parent class.
What should you pay attention to when rewriting?
1. The overridden method must have the same method name, parameter list and return value type as the original method (the return value type after Java SE5 can be a subtype of its type);
2. The overridden method cannot be a final type, because the final type cannot be overridden;
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3. The permissions of the overridden method cannot be private, because private cannot be inherited, and inheritance is the prerequisite for rewriting;
4. The overridden method cannot be static. If the method in the parent class is static, and The method of the subclass is not static, but except for this point, both methods meet the rewriting conditions, then a compilation error will occur, and vice versa;
If the methods in the subclass and the parent class are both static , and meet the rewriting conditions, but rewriting will still not occur because the static method matches the reference of the static method with the class at compile time;
5. Access to the rewritten method The permissions cannot be less than the original method;
6. The scope of the exception thrown by the rewrite cannot be greater than the original method;
7. The rewriting occurs at runtime, and the JVM will Decisions are made while the code is running.
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