Difference Between Float and Double

# Difference Between Float and Double

Vikram Singh
Assistant Manager - Content
Updated on Jun 12, 2023 14:47 IST

In this article we will discuss what is float, what is double in java, and the difference between them with the help of an example.

Float and Double are the most common data types used to store and manipulate numerical data. While both data types represent floating-point numbers (decimal numbers), some significant differences exist, including memory usage, precision, and performance characteristics. In this article, we will explore the difference between float and doubles in Java, and by the end, you will have a clear understanding of when to use each data type and why.

Let’s start the article with the tabular comparison between Float and Double in Java.

## What is Float in Java?

In Java, float is a primitive data type used to represent floating-point (decimal numbers) with single precision. These data types can have a fractional part, such as 3.14 or -0.567. To declare the float variable in Java, you must use the ‘float’ keyword followed by the variable name and optional initial value.

Example:

` `
`import java.util.*;public class Main{ public static void main(String[] args){ Scanner sc = new Scanner(System.in); System.out.println("Enter the radius of the circle : "); float radius = sc.nextFloat(); float area = (22.0f/7.0f) * radius * radius; System.out.println("Area of the Circle is "+ area +" sq. units"); } }Copy code`

Output

## What is Double in Java?

Similar to the float, double is also a primitive data type that is used to represent a floating number with double precision. It means the number can have a large range and greater precision than float numbers, but a double variable takes more memory than float data variables. To declare the double data type, you must use the ‘double’ keyword followed by the variable name and optional initial value.

Example

` `
```import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); System.out.println("Enter the radius of the circle: "); // Use double to allow for fractional radius double radius = scanner.nextDouble(); // Calculate the area double area = Math.PI * Math.pow(radius, 2); System.out.println("The area of the circle is: " + area); }}Copy code```

Output

## What are the key differences and similarities between Float and Double?

• Float takes up to 4 bytes of memory, while double takes up to 8 bytes.
• i.e., a double variable takes twice as much memory as a float variable.
• Float variables have a precision of about 7 decimal digits, whereas double variables have a precision of about 15-16 decimal digits.
• i.e., a double variable can represent the number with greater accuracy than float variables.
• The double variable is generally slower than the double variable as it requires high memory and high computational time.
• Floats and doubles are used to represent floating-point numbers.
• Both can be used in arithmetic operations like addition, subtraction, multiplication, and division.

## Use Cases of Floats and Doubles in JAVA

### When to use Float in JAVA?

Float is used when the application requires moderate precision and is sensitive to memory usage.

Example

• Graphical programming, where single-precision calculations are often sufficient for rendering images and animation.
• Embedded Systems, where memory resources are limited.
• Non-critical calculations, where minor inaccuracies are acceptable.

### When to use Double in JAVA?

Double is used when the application requires high precision and accuracy.

Example:

• Scientific calculation where accurate calculations are crucial for reliable results.
• Financial application, where small inaccuracies lead to significant errors.
• Meteorological Systems, where precise coordinates are required for accurate mapping.

## Conclusion

In this article, we have briefly discussed the two different data types that are used for numerical variables, i.e., floats and double, with the help of examples. The article also covers the difference between floats and doubles and uses cases of when to use float and when to use double.

Hope you will like the article.

Keep Learning!!