The Long.doubleValue()
method in Java is used to convert a Long
object to a double
primitive.
Table of Contents
- Introduction
doubleValue()
Method Syntax- Examples
- Converting a
Long
todouble
- Performing Arithmetic Operations
- Handling
null
Values
- Converting a
- Real-World Use Case
- Conclusion
Introduction
The Long.doubleValue()
method is an instance method in the Long
class in Java. It converts a Long
object to a double
primitive. This method is useful when you need to perform operations that require double
precision on Long
objects.
doubleValue()() Method Syntax
The syntax for the Long.doubleValue()
method is as follows:
public double doubleValue()
The method returns:
- The
double
value represented by thisLong
object.
Examples
Converting a Long
to double
The doubleValue()
method can be used to convert a Long
object to a double
primitive.
Example
public class LongToDoubleExample {
public static void main(String[] args) {
Long longObject = 123456789L;
double doubleValue = longObject.doubleValue();
System.out.println("Double value of 123456789L: " + doubleValue);
}
}
Output:
Double value of 123456789L: 1.23456789E8
In this example, the Long
object 123456789L
is converted to the double
primitive 1.23456789E8
.
Performing Arithmetic Operations
You can use the doubleValue()
method to extract the double
primitive from a Long
object and perform arithmetic operations.
Example
public class ArithmeticOperationsExample {
public static void main(String[] args) {
Long longObject1 = 500L;
Long longObject2 = 200L;
double sum = longObject1.doubleValue() + longObject2.doubleValue();
double difference = longObject1.doubleValue() - longObject2.doubleValue();
double product = longObject1.doubleValue() * longObject2.doubleValue();
double quotient = longObject1.doubleValue() / longObject2.doubleValue();
System.out.println("Sum: " + sum);
System.out.println("Difference: " + difference);
System.out.println("Product: " + product);
System.out.println("Quotient: " + quotient);
}
}
Output:
Sum: 700.0
Difference: 300.0
Product: 100000.0
Quotient: 2.5
In this example, the Long
objects 500L
and 200L
are converted to double
primitives, and arithmetic operations are performed on them.
Handling null
Values
When dealing with Long
objects, it’s important to handle null
values to avoid NullPointerException
.
Example
public class NullHandlingExample {
public static void main(String[] args) {
Long longObject = null;
if (longObject != null) {
double doubleValue = longObject.doubleValue();
System.out.println("Double value: " + doubleValue);
} else {
System.out.println("The Long object is null.");
}
}
}
Output:
The Long object is null.
In this example, the code checks if the Long
object is null
before attempting to convert it to a double
primitive.
Real-World Use Case
Converting User Input
In a real-world application, you might need to convert user input, which is often in the form of Long
objects, to double
primitives for calculations that require higher precision.
Example
import java.util.Scanner;
public class UserInputExample {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("Enter a long number: ");
Long longObject = scanner.nextLong();
double doubleValue = longObject.doubleValue();
double result = doubleValue * 1.5;
System.out.println("The result of multiplying the input by 1.5 is: " + result);
scanner.close();
}
}
Output (example input 123456789):
Enter a long number:
The result of multiplying the input by 1.5 is: 1.851851835E8
In this example, the user input is read as a Long
object and then converted to a double
primitive for a calculation.
Conclusion
The Long.doubleValue()
method in Java is a straightforward way to convert Long
objects to double
primitives. By understanding how to use this method, you can efficiently handle tasks that involve converting Long
objects to double
primitives in your Java applications. Whether you are performing arithmetic operations, handling user input, or avoiding null
values, the doubleValue()
method provides a reliable solution for these tasks.