In many programming languages such as C or Pascal,most users have come across global variables.Like this C example:
int GlobVar = 0; // Global variable void f(int x) // Function to change variable. { GlobVar = x; }
Java does not have such variables. However, there is a simple way to get around this, wrap the code in class declarations?like so:
public class GlobalVariables { public static int v = 0; public static void f(int x) {v = x;} }
[v] may be refered to with with: [GlobalVariables.v]
Note that the [static] keyword is used in declaring these classmembers so that they do not reference or operate on specific classobject instances. [final] may be used in declaration to “finalize” avalue, i.e., make it a constant. Related constants may be grouped like so:
public class body { public static final long text = 0xffffff; // Fixed [final] used public static final long bgcolor = 0; // Fixed [final] used public static long link = 0xff0000; // Changeble: [final] not used public static long vlink = 00ff00; // Changeble: [final] not used}public class keyboard { public static final String layout = "US"; // Fixed [final] used public static final String keys = 101; // Fixed [final] used}
Individual constants may be refered to with expressions like these:
int k = keyboard.keys; long linkcolor = body.link;
Note if you’re using a class simply for packaging purposes (likethis), it really doesn’t make sense to create a new instance of theclass. So, you can declare a private constructor:
private Body() {}
A constructor executes when an instance of the class is created, butnot with a private constructor.