Data Types in Prolog
Prolog is a logic programming language that supports several data types. Here are some of the main data types in Prolog with examples:
- Atom: An atom is a constant with a name that starts with a lowercase letter or a single quote. Atoms are often used to represent names, labels, and constants.
- Number: A number is a constant that represents a numerical value. Prolog supports integers, floating-point numbers, and scientific notation.
- Variable: A variable is a placeholder that can stand for any term. Variables start with an uppercase letter or an underscore.
- List: A list is a collection of terms enclosed in square brackets, separated by commas. Lists can contain any Prolog terms, including other lists.
[1, 2, 3]
[apple, orange, banana]
[1, [2, 3], 4]
 % an empty list
- Structure: A structure is a compound term that consists of a functor (an atom) and one or more arguments. The number of arguments is called the arity of the structure.
person(john, 25, male)
6. Boolean: Prolog does not have a built-in Boolean data type, but Boolean values can be represented as atoms or variables. Conventionally, the atom
true represents true and the atom
false represents false.
X = true % variable X can be true or false
These are some of the main data types in Prolog. It's worth noting that Prolog is a dynamically typed language, so variables can change their type during execution.