# What Is Fortran Data Type?

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Heather Bennett

What Is Fortran Data Type?

Fortran is a programming language that was developed in the 1950s for scientific and engineering calculations. As with any programming language, Fortran uses different data types to store and manipulate data. Understanding these data types is essential for writing efficient and error-free Fortran programs.

## Numeric Data Types

In Fortran, there are several numeric data types that you can use to store numbers. These include:

• Integer: Used to store whole numbers without fractional parts. For example, variables of type INTEGER can hold values like -10, 0, or 42.
• Real: Used to store floating-point numbers with both integer and fractional parts.

Variables of type REAL can hold values like -3.14, 0.0, or 1e10.

• Double Precision: Similar to REAL but provides higher precision by using twice as many bits to represent the number. Variables of type DOUBLE PRECISION are typically used when greater accuracy is required.

## Character Data Types

In addition to numeric data types, Fortran also provides character data types for storing text. The main character data types in Fortran are:

• Character: Used to store a single character or a sequence of characters. Variables of type CHARACTER can hold values like ‘A’, ‘Hello’, or ‘123’.

## Logical Data Type

The logical data type in Fortran is used to represent Boolean values (i.e., true or false). Variables of type LOGICAL can hold one of two values: .TRUE.

or .FALSE.. This data type is commonly used in conditional statements and logical operations.

## Derived Data Types

Fortran also allows you to create your own data types using derived types. Derived types are structures that can contain multiple components of different data types. They provide a way to organize related data into a single entity.

### Example:

Consider the following example where we define a derived type called Person:

```  ```
TYPE :: Person
CHARACTER(LEN=20) :: name
INTEGER :: age
LOGICAL :: isMale
END TYPE Person
```
```

In this example, the derived type “Person” has three components: a character variable “name” to store the person’s name, an integer variable “age” to store their age, and a logical variable “isMale” to represent their gender.

By using derived types, you can create complex data structures that can hold multiple pieces of information together, making your code more organized and easier to maintain.

## Conclusion

In Fortran, data types play a vital role in programming. They define the kind of data that can be stored in variables and dictate how that data can be manipulated. By understanding and utilizing the various Fortran data types effectively, you can write more efficient and reliable programs.