CODEWITHSUNDEEP
javafloating-pointminimum
Jérôme Verstrynge
Jérôme Verstrynge

Reputation: 59576

Maximum value for Float in Java?

The following question indicates that the minimum value of a Double is -Double.MAX_VALUE. Is this also true for Float (i.e., -Float.MAX_VALUE)?

Upvotes: 31

Views: 121946

Answers (5)

R.D. Alkire
R.D. Alkire

Reputation: 522

EDIT: My original answer appears to be badly incorrect. Thank you @aioobe for pointing this out.

Instead, using the magic of java code to answer the title question:

System.out.printf( "Float.MAX_VALUE: %,f\n", Float.MAX_VALUE );

Float.MAX_VALUE: 340,282,346,638,528,860,000,000,000,000,000,000,000.000000

System.out.printf("in scientific notation: %.18g\n", Float.MAX_VALUE );

in scientific notation: 3.40282346638528860e+38

System.out.printf(
            "in hexadecimal floating-point number with a significand and "
            + "an exponent: %a", Float.MAX_VALUE );

in hexadecimal floating-point number with a significand and an exponent: 0x1.fffffep127

Upvotes: 19

Alexander Pogrebnyak
Alexander Pogrebnyak

Reputation: 45576

Yes, it's also true for Float.

For more information check the manual here http://download.oracle.com/javase/7/docs/api/java/lang/Float.html

Upvotes: 6

fvu
fvu

Reputation: 32953

Yes it is, and for exactly the same reason as stated in the answer for the question you linked, Floats and Doubles use IEEE754 representation which is "symmetrical" due to the way they are stored.

Upvotes: 1

Jon Skeet
Jon Skeet

Reputation: 1500055

Yes - it's the same bit pattern as Float.MAX_VALUE except with the sign bit flipped... and that's another way to get at the value:

public class Test {
    public static void main(String[] args) {
        // Float.MAX_VALUE is intBitsToFloat(0x7f7fffff)
        // so we set the most significant bit - the sign bit
        float f = Float.intBitsToFloat((int) 0xff7fffff);
        System.out.println(f == -Float.MAX_VALUE); // true
    }
}

Upvotes: 20

dlev
dlev

Reputation: 48596

Yes, -Float.MAX_VALUE is the negative number with largest magnitude. floats are represented the same way as doubles, just with half the storage space (and the accompanying loss of precision.) Since signs in IEEE 754 are represented by a single bit, flipping that bit doesn't change the overall magnitude attainable by the remaining bits.

Upvotes: 31

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