java-final keywords

Final: Finally, that's it.

In three different situations:

1. Decoration class

Indicates that the class cannot be inherited and extended

Final class A {} class extends A {}//  Compiler error indicating that it cannot inherit

2. Modification method

Subclasses cannot overwrite and override this method

class a {    finalvoid  method () {}}classextends  A {    @ Override    void method () {}//  compiler Error, unable to override it }

3. Modifier variables

For an object, the reference to the variable is guaranteed to be unchanged and its value can be modified

For basic type data, the guaranteed value is the same. Same as when modifying method parameters

 Public classFinaldemo { Public Static voidMain (string[] args) {String a= "Hello2"; FinalString B = "Hello"; String C= B + 2;        System.out.println (A.equals (c)); String D= "Hello"; String e= d + 2;                System.out.println (A.equals (e)); Modify the value of the current objectFinalStringBuffer Tempbuffer =NewStringBuffer ("Hello, world!"); Tempbuffer.append ("This is final string!"); //Tempbuffer = new StringBuffer ();//Unable to re-reference data    }}

java-final keywords