# What Is Double Data Type?

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Scott Campbell

A double data type is a fundamental data type in programming that is used to represent decimal numbers with a higher precision than the float data type. It is often used when more accurate calculations or storage of large decimal numbers are required.

## Definition

The double data type, also known as double precision floating-point format, is a numeric data type that can store both positive and negative decimal numbers. It provides a wider range of values and greater precision compared to the float data type.

## Declaration and Initialization

To declare a variable of double data type in most programming languages, you can use the following syntax:

```double variableName; // Declaration
variableName = value; // Initialization
```

You can also declare and initialize a variable in a single line:

```double variableName = value;
```

## Precision and Range

The double data type typically uses 64 bits to represent a floating-point number. This allows it to store values with up to 15 decimal digits of precision. The actual precision may vary slightly depending on the programming language and platform.

The range of values that can be represented by the double data type depends on the specific implementation but is usually between approximately ±1.7 × 10-308 to ±1.7 × 10+308. This makes it suitable for a wide range of applications that require precise calculations or handling large numbers.

## Usage Examples:

The double data type can be used in various scenarios, such as:

• Financial calculations involving currency exchange rates or interest rates
• Scientific calculations requiring high precision, such as physical simulations or astronomical calculations
• Storing and manipulating large decimal numbers, such as measurements or sensor data

## Differences from the Float Data Type

The double data type differs from the float data type primarily in terms of precision and range. While the float data type uses 32 bits to represent a floating-point number and provides approximately 7 decimal digits of precision, the double data type uses 64 bits and provides around 15 decimal digits of precision.

### Summary:

The double data type is a fundamental numeric data type used to represent decimal numbers with higher precision than the float data type. It offers a wider range of values and greater accuracy, making it suitable for various applications that require precise calculations or handling of large decimal numbers.