Glossary

# Boolean

Variable type named after George Boole who invented the representation of data with either true or false (or 0s and 1s). A boolean can therefore take on the value of either true or false. Conditional statements are boolean expressions. A boolean variable b may be filled thus (among other ways):
``` b := (y = 2);```
If y is 2 then b will become true, otherwise b will be false.

# Constant

A value which is set at design time, which cannot be changed during program execution. It may be use for things such as the number of feet in a mile, to make your code more readable.

# Function

A
procedure that returns a value. A function to return the interest on a bank account would be better practice than a procedure which put the value into a global variable.

# Keyword

A word, reserved by Pascal, for special use. Such as the program keyword which is reserved for declaration of the program name. Keywords cannot be used for any other purpose. They are also sometimes called reserved words.

# Ordinal Types

A type which contains a single value defining a place in an order. Hence, ordinal. In pascal the only types that are not ordinal are string, array, record and object types.

# Procedure

A block of instructions which can be called with a reference to the procedure name. A procedure can take parameters. Normally used for code which is used a number of times throughout the program. For instance you might make a procedure to calculate the interest on a bank account, and each time, pass it the account balance and the interest rate. It could check for being below the minimum to get any interest, etc.

# Reserved Word

A word, reserved by Pascal, for special use. Such as the program reserved word which is reserved for declaration of the program name. Reserved words cannot be used for any other purpose. They are also sometimes called keywords.

# Syntax

The syntax of a command is how it is written.
e.g the readln command is written like so:--
` readln (<string value>); `

# Variable

Reference to a memory address which can store information. What I mean is if you declare i as an Integer, it has a variable value, such that it may change throughout your program, or it may be set once, and that value checked.