final variable - Moe no Kengpian Bay Tree

final keyword can be modified to different content, which includes only one variable, a method, or a class, the following are final modified the content of the role:
　　final variable: indicates that the variable is a constant that can only be initiated once a final method: Indicates that the the method can not be overridden
　　final class: this class can not be inherited represents the
　　final variable
　　when a variable is modified final keyword means that its value can not be changed, that is to say, this variable represents a constant. This also means that the final variable must be initialized. Is a reference to an object if a final variable represents, then that variable will not be able to re-express reference to another object, but the final internal state variable points to the object can be changed, for example, we can array to a final or final collection of add or delete elements. In addition, the use of capital letters and underlined a final variable is a good habit.
　　Examples
　　// A variable Final
　　Final the THRESHOLD = int. 5;
　　// A blank variable Final
　　Final int the THRESHOLD;
　　// A static variable Final the PI
　　static Double Final the PI = 3.141592653589793; // A static variable blank Final
　　static Double Final the PI;
　　initialize a final variables
　　final variable - Meng Pui tree without Kengpian, we must initialize a final variable, or the compiler will throw an error. A final variable can be initialized only once, it can be initialized by initializing the device or its initialization statement. There are three ways to initialize a final variable:
　　to align initialized when they are declared final variable, which is the most common way to initialize. When a final variable is not initialized when declared, this variable is to become blank final variable, then the following two methods is to initialize a blank final variable blank finalfinal variable - Moe no Kengpian Bay Tree, variables can code consists instance-initializer block or constructor initializes. If you have multiple constructors, then the blank final variable must be initialized in every constructor, otherwise a compile-time error.
　　A blank static final variables can be initialized Examples static code block inside
　　// Initialize method final variable
　　class the Test {
　　// Initialization directly
　　final int = the THRESHOLD. 5;
　　// blank final variable
　　final int in CAPACITY;
　　final int maxmum;
　　// Blanck static final variable
　　static final int MINIMUM;
　　// use initializer
　　{
　　CAPATICY = 25;
　　}
　　// use the static block
　　static {
　　= 125 maxmum;
　　}
　　// constructor using
　　public the Test () {
　　MINIMUM = -1;
　　}
　　}