Digital development concepts
Computer programs use A data store is a location for keeping and managing collections of data including databases and simpler types such as files and emails to organise different data within a program.
Data can be constant or variable within programs and functions. When we create a program, we also need to create ways for users to input data into the program and output information from it.
Input, output, variables, constants and assignment
To store data within a computer program you need to create a data store. This can either be a constant, a A named storage location. The value of a variable can change or an A set of data values of the same type, stored in a sequence in a computer program. Also known as a list. .
Variables
A variable is a named memory location. Data stored in that location changes throughout the duration of the program, for example the high score in a computer game.
When we create a variable, we allocate a space in the memory for it and give it a name.
We give variables names as identifiers to help explain the value assigned to it. For example, age = 16.
We assign values to variables using an Setting the value of a variable in a computer program. operator. For example, = (the 'equals' sign).
We can change the value of our variable at any time during the running of a program. For example, age = age + 1. Here, we have added 1 to the value of the variable 'age'. The age variable will now store the value 17.
Constants
A constant is a named location in memory that contains a value, that does not change during the execution of a program. Data is assigned to a constant in the same way as a variable. For example, in a computer game:
CONST CHARACTERSPEED = 5
CONST GRAVITY = -5When writing code, we often use UPPER CASE to help identify constants.
Arrays
If you need to store multiple values you will need to use an A set of data values of the same type, stored in a sequence in a computer program. Also known as a list. . This is a set of values of the same The format in which a variable or constant holds data, such as ‘integer’ or ‘string’. stored under one identifier.
Input functions
To get input from a user we have to use an A group of instructions, also known as a procedure. The input function is used to ask the user a question, and invites them to give a response. This value of this user response is then returned as the result of the function, and is stored in a variable. By default, this will be a A sequence of characters often stored as a variable in a computer program. These characters can include numbers, letters and symbols. , however we can use A way to convert a variable from one data type to another data type. Such as string to integer. (converting one data type into another) to change the data type. For example:
To output information from a computer program we use a A set of code instructions that tell a computer how to run a program (this is not used for printing output on to paper). Most programming languages will provide a print procedure for writing or displaying information to the screen. For example:
