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Java Datatypes → Double in Java

Java Datatypes

Double in Java

What is Double in Java

Double datatype

The double datatype is a double-precision floating-point number. This means that it can store values from approximately 4.9e-324 to approximately 1.8e308. Double variables are declared by using the double keyword. For example,
Java double declaration
double a, b; double c=123.555646; double d= 134.3245+432; double e="fff"; //wrong declaration double f=2434.5546657766;
Another example,
Java double datatype basic example
public class Main{ public static void main(String[] args) throws Exception { double pi = 3.14159; double rad = 10; double area = pi * rad * rad; System.out.println("Area of a circle with radius 10 is " + area); } }


Area of a circle with radius 10 is 314.159
Double variables are often used to store data that requires a high degree of precision. They are also useful when working with data that is outside the range of the float data type. Precision and Range: The double datatype offers higher precision compared to the float datatype. It can represent a wide range of decimal values with greater accuracy for both small and large numbers. Memory: The double datatype uses 64 bits (8 bytes) of memory, which makes it more memory-intensive compared to the float datatype. Operations: You can perform arithmetic and mathematical operations on double values, similar to other numeric datatypes. Type Casting: When performing operations involving double and other numeric types (such as float), you might need to explicitly cast the values to avoid potential data loss. Use Cases: The double datatype is often used in scenarios where precision is critical, such as scientific calculations, financial applications, simulations, and tasks involving extremely small or large numbers. Considerations: While double provides high precision, it uses more memory than float. In situations where memory efficiency is crucial, or when computations involve extremely large datasets, other considerations might come into play. Default for Decimal Literals: In Java, decimal literals without a suffix are interpreted as double by default. For example, 3.14 is treated as a double literal.