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Guava - Doubles Class
Doubles is a utility class for primitive type double.
Class Declaration
Following is the declaration for com.google.common.primitives.Doubles class −
@GwtCompatible(emulated = true) public final class Doubles extends Object
Fields
Sr.No | Field & Description |
---|---|
1 |
static int BYTES The number of bytes required to represent a primitive double value. |
Methods
Sr.No | Method & Description |
---|---|
1 |
static List<Double> asList(double... backingArray) Returns a fixed-size list backed by the specified array, similar to Arrays.asList(Object[]). |
2 |
static int compare(double a, double b) Compares the two specified double values. |
3 |
static double[] concat(double[]... arrays) Returns the values from each provided array combined into a single array. |
4 |
static boolean contains(double[] array, double target) Returns true if target is present as an element anywhere in array. |
5 |
static double[] ensureCapacity(double[] array, int minLength, int padding) Returns an array containing the same values as the array, but guaranteed to be of a specified minimum length. |
6 |
static int hashCode(double value) Returns a hash code for value; equal to the result of invoking ((Double) value).hashCode(). |
7 |
static int indexOf(double[] array, double target) Returns the index of the first appearance of the value target in array. |
8 |
static int indexOf(double[] array, double[] target) Returns the start position of the first occurrence of the specified target within array, or -1 if there is no such occurrence. |
9 |
static boolean isFinite(double value) Returns true if value represents a real number. |
10 |
static String join(String separator, double... array) Returns a string containing the supplied double values, converted to strings as specified by Double.toString(double), and separated by separator. |
11 |
static int lastIndexOf(double[] array, double target) Returns the index of the last appearance of the value target in array. |
12 |
static Comparator<double[]> lexicographicalComparator() Returns a comparator that compares two double arrays lexicographically. |
13 |
static double max(double... array) Returns the greatest value present in array, using the same rules of comparison as Math.max(double, double). |
14 |
static double min(double... array) Returns the least value present in array, using the same rules of comparison as Math.min(double, double). |
15 |
static Converter<String,Double> stringConverter() Returns a serializable converter object that converts between strings and doubles using Double.valueOf(java.lang.String) and Double.toString(). |
16 |
static double[] toArray(Collection<? extends Number> collection) Returns an array containing each value of collection, converted to a double value in the manner of Number.doubleValue(). |
17 |
static Double tryParse(String string) Parses the specified string as a double-precision floating point value. |
Methods Inherited
This class inherits methods from the following class −
- java.lang.Object
Example of Doubles Class
Create the following java program using any editor of your choice in say C:/> Guava.
GuavaTester.java
import java.util.List; import com.google.common.primitives.Doubles; public class GuavaTester { public static void main(String args[]) { GuavaTester tester = new GuavaTester(); tester.testDoubles(); } private void testDoubles() { double[] doubleArray = {1.0,2.0,3.0,4.0,5.0,6.0,7.0,8.0,9.0}; //convert array of primitives to array of objects List<Double> objectArray = Doubles.asList(doubleArray); System.out.println(objectArray.toString()); //convert array of objects to array of primitives doubleArray = Doubles.toArray(objectArray); System.out.print("[ "); for(int i = 0; i< doubleArray.length ; i++) { System.out.print(doubleArray[i] + " "); } System.out.println("]"); //check if element is present in the list of primitives or not System.out.println("5.0 is in list? " + Doubles.contains(doubleArray, 5.0f)); //return the index of element System.out.println("5.0 position in list " + Doubles.indexOf(doubleArray, 5.0f)); //Returns the minimum System.out.println("Min: " + Doubles.min(doubleArray)); //Returns the maximum System.out.println("Max: " + Doubles.max(doubleArray)); } }
Verify the Result
Compile the class using javac compiler as follows −
C:\Guava>javac GuavaTester.java
Now run the GuavaTester to see the result.
C:\Guava>java GuavaTester
See the result.
[1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0] [ 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 ] 5.0 is in list? true 5.0 position in list 4 Min: 1.0 Max: 9.0