Data Types, Data Structures and Algorithms

An integer is a whole number.

A real or a float is a number with a decimal point.

A boolean can be either true or false.

A char is a single letter, number or symbol.

A string is zero or more characters joined together.

A character set is a collection of characters and the corresponding binary codes used to represent them.

ASCII (American Standard Code for Information Interchange) uses 7 bits to represent characters, and so can represent a maximum of 128 different characters.

This means that ASCII is not sufficient to represent all of the languages in the world, or all of the possible numbers / symbols.

Unicode fixes this problem, using many more bits to represent each character, and so can represent every character from every alphabet and a variety of special symbols.

A static data structure cannot change size during runtime, whereas a dynamic data structure can.

An array is a static data structure that stores related data items of the same data type. Each item can be accessed directly by its index.

A record is a data type that consists of a fixed number of variables, called fields. Each field has a name and a data type.

A list is a dynamic data structure, consisting of an ordered set of data. Each item can be accessed directly by its index.

Something that is immutable cannot have its value changed during runtime.

A tuple is an immutable list.