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.
Open your Java Integrated Development Environment (IDE).
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;
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();
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.