Java Language Tutorial => The double primitive

Example

A double is a double-precision 64-bit IEEE 754 floating point number.

double example = -7162.37;
double myDouble = 974.21;
double anotherDouble = 658.7;

double addedDoubles = myDouble + anotherDouble; // 315.51
double subtractedDoubles = myDouble - anotherDouble; // 1632.91

double scientificNotationDouble = 1.2e-3;    // 0.0012

Because of the way floating point numbers are stored, many numbers don't have an exact representation.

double notExact = 1.32 - 0.42; // result should be 0.9
System.out.println(notExact); // 0.9000000000000001

While using double is fine for most applications, neither float nor double should be used to store precise numbers such as currency. Instead, the BigDecimal class should be used

The default value of a double is 0.0d

public double defaultDouble;    // defaultDouble == 0.0

Note: Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY, Double.NaN are double values. NaN stands for results of operations that cannot be determined, such as dividing 2 infinite values. Furthermore 0d and -0d are different, but == yields true:

double d1 = 0d;
double d2 = -0d;
System.out.println(d1 == d2); // true
System.out.println(1d / d1); // Infinity
System.out.println(1d / d2); // -Infinity
System.out.println(Double.POSITIVE_INFINITY / Double.POSITIVE_INFINITY); // NaN

PDF - Download Java Language for free

Previous Next

Java Language

Fastest Entity Framework Extensions

Example

Got any Java Language Question?

Java Language

Java Language Primitive Data Types The double primitive

Fastest Entity Framework Extensions

Example

Got any Java Language Question?