Java Math random()
random() returns a double value greater than or equal to 0 and less than 1.0.
Following is the syntax of random() method.
double n = random()
random() method uses the pseudo-random number generator function java.util.Random().
Example 1 – Math.random()
In the following example, we use random function to generate a random number in the range [0.0, 1.0).
Java Program
public class MathExample {
public static void main(String[] args) {
double n = Math.random();
System.out.println(n);
}
}
Output
0.8503998521780656
Example 2 – Math.random() – Generate Random Double from [min, max)
You can use random() method to generate a random number between a given minimum and a maximum.
In the following program, we will generate a random double number in the range [min, max).
Java Program
public class MathExample {
public static void main(String[] args) {
double min = 2.65;
double max = 8.693;
double n = min + (max-min)*Math.random();
System.out.println(n);
}
}
Output
4.723410184654693
Example 3 – Math.random() – Random Integer in [min, max)
If any of the base or height is infinite, then the length of hypotenuse is infinite, and random() returns positive infinite.
Java Program
public class MathExample {
public static void main(String[] args) {
int min = 20;
int max = 80;
int n = (int) (min + (max-min)*Math.random());
System.out.println(n);
}
}
Output
34
Conclusion
In this Java Tutorial, we learned about Java Math.random() function, with example programs.