Though it is impossible for a computer to literally represent the value of infinity in memory, the Java "double" and "float" data-type reserves two slots in its address range that are understood by the computer to refer to positive and negative infinity.

## Step 1

Open your Java Integrated Development Environment (IDE).

## Step 2

Type the following to define a double (or float) with a value of positive or negative infinity:

double pInfiniteDouble = Double.POSITIVE_INFINITY; double nInfiniteDouble = Double.NEGATIVE_INFINITY; float pInfiniteFloat = Float.POSITIVE_INFINITY; float nInfiniteFloat = Float.NEGATIVE_INFINITY;

## Step 3

Check to see if a double or float has a value of infinity using the "isInfinite()" method:

pInfiniteDouble.isInfinite(); nInfiniteDouble.isInfinite(); pInfiniteFloat.isInfinite(); nInfiniteFloat.isInfinite();

### Tip

There is one other odd value defined in the Double and Float data types: NotaNumber (NAN). It is accessed with "Double.NaN" or "Float.NaN."

Infinity and NaN are returned by some trigonometric and logarithmic functions in the Java math package.