Java examples for Language Basics:double
Java double data type uses 64 bits to store a floating-point number in the IEEE 754 format.
A double literal may optionally end with d or D, for example, 12.12d.
The suffix d or D is optional in double literals.
both 12.12 and 12.12d represent the same double literal.
A double literal can be expressed in the following two formats:
double d1 = 8D double d2 = 8.; double d3 = 8.0; double d4 = 8.D; double d5 = 7128.981267; double d6 = 45.12;
You can also use scientific notation to express double literals.
double d1 = 32.5E-1; double d2 = 0.325E+1; double d3 = 0.325E1; double d4 = 0.0325E2; double d5 = 0.0325e2; double d6 = 32.5E-1D; double d7 = 0.325E+1d; double d8 = 0.325E1d; double d9 = 0.0325E2d;
The following table lists these constants and their meanings.
| double Constants | Meaning |
|---|---|
| Double.POSITIVE_INFINITY | Positive infinity of type double |
| Double.NEGATIVE_INFINITY | Negative infinity of type double |
| Double.NaN | Not a Number of type double |
| Double.MAX_VALUE | The largest positive value that can be represented in a double variable. |
| Double.MIN_VALUE | The smallest positive value greater than zero that can be represented in a double variable. |
The value of all integral types (int, long, byte, short, char) and float can be assigned to a variable of the double data type without using an explicit cast.
int num1 = 15000; double salary = num1; // Ok. int to double assignment salary = 12455; // Ok. int literal to double double bigNum = Double.MAX_VALUE; // Assigns the maximum double value bigNum = 1226L; // Ok, long literal to double double justAChar = 'A'; // Ok. Assigns 65.0 to justAChar double dInf = Double.POSITIVE_INFINITY; // Ok. Assigns positive infinity to dInf variable double dNan = Double.NaN; // Ok. Assigns Not-a-Number to dNan variable double dTooBig = 1.8E308; // A compile-time error. to large double dTooSmall = 4.9E-325; // A compile-time error. too small
A double value must be cast to the integral type (int, long, byte, short, or char) when assigning.
int num1 = 10; double salary = 10.0; num1 = salary; // A compile-time error. Cannot assign double to int num1 = (int)salary; // Now Ok.