Static final constant

Package oo.day06;
Static final constant
public class Staticfinaldemo {
public static void Main (string[] args) {
Aoo.num = 250; Compilation errors, constants cannot be modified
System.out.println (Aoo.num);

1. Loading Boo.class in the method area
2. Storing NUM1 in the method area
3. Go to the method area to get the value of the NUM1 and output
System.out.println (BOO.NUM1);

The compiler is directly replaced with a specific value at compile time, high efficiency
Equivalent to SYSTEM.OUT.PRINTLN (6);
System.out.println (BOO.NUM2);
}
}
Class boo{
public static int NUM1 = 5; static variables
public static final int NUM2 = 6; Constant
}

Class aoo{
public static final int NUM = 5; Constant
public static final double PI; Compile error, must declare simultaneous initialization
}

Static final constant