Question

What’s the difference between Float.POSITIVE_INFINITY and Float.MAX_VALUE?
Which is greater?
Are they the same?

I came accross them looking for a value that would be greater than every other float or failing that all except the greatest. Does either meet that criteria?

Thanks!

Answer 1

No, they’re not the same thing at all.

Float.MAX_VALUE is the largest finite value that can be represented in a float. You won’t find any value greater than that, other than infinity. But you can perform all kinds of other operations on it.

Float.POSITIVE_INFINITY is, well, infinity. Most operations involving an infinity will end up with infinity (either positive or negative).

For example:

public class Test {
    public static void main(String[] args) {
        testOperations(Float.MAX_VALUE);
        testOperations(Float.POSITIVE_INFINITY);
    }

    public static void testOperations(float input) {
        System.out.println("input: " + input);
        System.out.println("input / 100: " + input / 100);
        System.out.println("input * 100: " + input * 100);
        System.out.println("-input: " + (-input));
        System.out.println();
    }
}

Output:

input: 3.4028235E38
input / 100: 3.4028236E36
input * 100: Infinity
-input: -3.4028235E38

input: Infinity
input / 100: Infinity
input * 100: Infinity
-input: -Infinity