In the first article on generating random numbers the focus was on generating whole numbers. Sometimes however it's useful to be able to generate random fractional numbers or even boolean values.

### Generating a Random Number Between 0 and 1

There are two options to pick from when looking to generate a fractional number between 0 and 1. The first is to continue to use the Random object. The nextDouble() method will return a fractional number as a double data type:

```
Random rand = new Random();
Double pickedNumber = rand.nextDouble();
```

which will produce a number like:

` 0.823047216371369 `

Note: there is a nextFloat() method which will also give you a random fractional number except that instead of returning a double data type it returns a float.

Alternatively, there is a simpler way that doesn't involve the need to explicitly create a random number generator object. Instead the random static method from the Math class can be used:

```
double pickedNumber = Math.random();
System.out.print(pickedNumber);
```

Like the nextDouble() method the number produced is a double between 0 and 1:

` 0.6563300920283471 `

There is no real difference between the two options because the Math.random() method creates a random number generator of its own. It just saves you having to do so yourself.

Generally I use Math.random() if I don't already have a random object created. For example, if I wanted to generate a random fractional number between 30.0 and 40.0 then I would create a Random object and use both the nextInt() and nextDouble() methods:

```
Random rand = new Random();
int wholePart = rand.nextInt(10) + 30;
double decimalPart = rand.nextDouble();
double pickedNumber = wholePart + decimalPart;
System.out.print(pickedNumber);
```

Which will produce a number like:

` 34.831550232183766 `

### How to Generate Random Boolean Values

There is one more method of the Random class that is worth looking at.

It is the nextBoolean() method. It produces a true or false with almost equal probability. For example, if I wanted to write a program that simulated the tossing of a coin fifty times I could do this:

```
boolean headsOrTails;
int headsCount = 0;
int tailsCount = 0;
Random rand = new Random();
for (int j=0;j < 50;j++)
{
headsOrTails = rand.nextBoolean();
if (headsOrTails == true)
{
headsCount++;
}
else
{
tailsCount++;
}
}
System.out.println("The virtual coin landed on heads " + headsCount + " times and on tails " + tailsCount + " times.");
```

After a bout of random virtual coin tossing I might get a result of:

` The virtual coin landed on heads 27 times and on tails 23 times. `