How to generate random positive and negative numbe

问题:

This question already has an answer here:

• How do I generate random integers within a specific range in Java? 62 answers

I am trying to generate random integers over the range (-32768, 32767) of the primitive data type short. The java Random object only generates positive numbers. How would I go about randomly creating numbers on that interval? Thanks.

回答1:

You random on (0, 32767+32768) then subtract by 32768

回答2:

Random random=new Random();
int randomNumber=(random.nextInt(65536)-32768);

回答3:

public static int generatRandomPositiveNegitiveValue(int max , int min) {
    //Random rand = new Random();
    int ii = -min + (int) (Math.random() * ((max - (-min)) + 1));
    return ii;
}

回答4:

Generate numbers between 0 and 65535 then just subtract 32768

回答5:

This is an old question I know but um....

n=n-(n*2)

回答6:

([my double-compatible primitive type here])(Math.random() * [my max value here] * (Math.random() > 0.5 ? 1 : -1))

example:

// need a random number between -500 and +500
long myRandomLong = (long)(Math.random() * 500 * (Math.random() > 0.5 ? 1 : -1));

回答7:

(Math.floor((Math.random() * 2)) > 0 ? 1 : -1) * Math.floor((Math.random() * 32767))

回答8:

In case folks are interested in the double version (note this breaks down if passed MAX_VALUE or MIN_VALUE):

private static final Random generator = new Random();
public static double random(double min, double max) {
    return min + (generator.nextDouble() * (max - min));
 }