The difference between c#override and the new modifier (reproduced)

C # is more than Java a new hidden feature. C # Override overrides a method rewrite that is equivalent to no keyword in java. So the method in Java has no hidden functionality.

C # Override overrides means overriding a virtual method (tag virtual) or abstract method (marked abstract) in a parent class to implement new functionality that must exactly match the signature of the parent class method, and that the accessibility of the parent class method must be consistent with the new hidden Is the same method of redefining a signature in a subclass as a method of the parent class, which can be used without a new modifier, except that a warning message pops up at compile time: if it is intentionally hidden, use the keyword new.

1 usingSystem; 2  Public classTest3 {     4      Public Static voidMain (string[] args) {5A a=NewB (); 6Console.Write (A.getval ());//output: A Although the instance is B, but the method of a is executed7     8A=NewC (); 9Console.Write (A.getval ());//output: The C instance is C, and C overrides the method of a, so the method of C is executedTen      OneB b=NewB ();  AConsole.Write (B.getval ());//Output: b The method of B is only executed if both the definition and the instance are B . -     }       - }      the classA - {      -     //to allow subclasses to be overridden, the method must be identified as virtual or abstract -      Public VirtualString getval () { +         return "A";  -     }       + }       A classb:a at {      -     //The hidden parent method is identified with the new, a compile warning is not identified, and does not affect the use of the -      Public NewString getval () { -         return "B";  -     }       - }       in classc:a - {      to     //The override method must be identified with the override +      Public OverrideString getval () { -         return "C";  the     }       *}

In Java, there is no concept of hiding the parent class method, Java has only the concept of overriding methods, and the same code, executed in Java and executed in C # is completely different:

1 classTest2 {     3      Public Static voidMain (string[] args)4     {     5A a=NewB (); 6 //output: The B instance is B, and the method of B is executed (in C #, this should output a)7 System.out.println (A.getval ()); 8A=NewA (); 9 //output: A method to execute a only if both the definition and the instance are aTen System.out.println (A.getval ());  One     }      A }      - classA - {      the      PublicString getval () { -         returnA;  -     }       - }       + classBextendsA - {      +      PublicString getval () { A         returnB;  at     }       -}

PS: Reproduced from 51CTO only for my study and use

The difference between c#override and the new modifier (reproduced)