2.2 Programming Fundamentals

Variable

Variable

A named container that stores a value in memory, which can change its value while the program is running.

Constant

A named container that stores a value in memory, which cannot change its value while the program is running.

Operators

Symbols used to perform operations on variables and values, such as +, -, *, /, MOD, DIV, ^, ==, !=, <, <=, >, >=.

Assignment

The process of assigning a value to a variable, e.g., favNum = 5.

Input

The method of receiving data from the user, e.g., favNum = input("Type in your number").

Output

The method of displaying data to the user, e.g., print("your favourite number is", favNum).

Integer

A whole number, such as 1, 5, or -259.

Real / Float

Numbers that can have a fractional part, such as 1.5 or -125.1.

Boolean

A data type that can be either TRUE or FALSE (1 or 0).

Sequence

A set of instructions executed in order, line by line.

Selection

Instructions that do not have to be executed in sequence, based on the results of an event or condition.

Iteration

The repetition of a block of statements within a program.

Count-controlled iteration

A type of iteration with a fixed number of repetitions, e.g., for i in range(5, 10, 3).

Nested count-controlled iteration

A loop within another loop, e.g., for i in range(5) followed by another for loop.

Condition-controlled iteration

An indefinite iteration that continues based on a condition, e.g., while(i < 10).

Character

A single alphanumeric symbol, such as 'a', 'c', or '1'.

String

One or more alphanumeric characters, e.g., "abcd", "123", "12/01", "£3.50".

Casting

Changing how a variable’s data type is interpreted or a temporary conversion of data type.

Subroutines

A block of code executed whenever called, allowing code reuse and easier debugging.

Functions

A subroutine that returns a value.

Procedures

A subroutine that does not return a value.

Arrays

A collection of items stored at contiguous memory locations, e.g., favFoods = ["Chicken", "Fish and Chips"].