fixed floating point calculations in Java

In Java I need some hint to declare floating poin开发者_开发知识库t variable that in all virtual machine run uniquely and show number unique float number in all machine ( mobile machine and PC )

You can use strictfp keyword for class declaration or variables :

public strictfp class MyFPclass { 
    // ... contents of class here ...
}

The Java package java.lang.Math class contains these strictfp methods:

 public static strictfp double abs(double);
 public static strictfp int max(int, int);
 public static strictfp long max(long, long);
 public static strictfp float max(float, float);
 public static strictfp double max(double, double);
 public static strictfp int min(int, int);

I can suggest 2 classes for this purpose you can think of

1. Math.random()
2. java.util.Random class

The methods of the Random class often produce random numbers in a more convenient form, but requires creating an object, which sometimes is inconvenient. In constrast, the Math.random() method produces a double value which must sometimes be translated and cast into the form you need it. It's a tradeoff between the globalness of Math.random more directly useful numbers from the Random class.