D Programming - Data Types

In the D programming language, data types refer to an extensive system used for declaring variables or functions of different types. The type of a variable determines how much space it occupies in storage and how the stored bit pattern is interpreted.

The types in D can be classified as follows −

The array types and structure types are referred to collectively as the aggregate types. The type of a function specifies the type of the function's return value. We will see basic types in the following section whereas other types will be covered in the upcoming chapters.

Integer Types

The following table gives lists standard integer types with their storage sizes and value ranges −

To get the exact size of a type or a variable, you can use the sizeof operator. The expression type.(sizeof) yields the storage size of the object or type in bytes. The following example gets the size of int type on any machine −

import std.stdio; 
 
int main() { 
   writeln("Length in bytes: ", ulong.sizeof); 

   return 0; 
}

When you compile and execute the above program, it produces the following result −

Length in bytes: 8 

Floating-Point Types

The following table mentions standard float-point types with storage sizes, value ranges, and their purpose −

The following example prints storage space taken by a float type and its range values −

import std.stdio;

int main() { 
   writeln("Length in bytes: ", float.sizeof); 

   return 0; 
}

When you compile and execute the above program, it produces the following result on Linux −

Length in bytes: 4

Character Types

The following table lists standard character types with storage sizes and its purpose.

The following example prints storage space taken by a char type.

import std.stdio;

int main() {
   writeln("Length in bytes: ", char.sizeof);
   
   return 0;
}

When you compile and execute the above program, it produces the following result −

Length in bytes: 1

The void Type

The void type specifies that no value is available. It is used in two kinds of situations −

The void type may not be understood to you at this point, so let us proceed and we will cover these concepts in upcoming chapters.