Variables and Arrays

Basic Types

• integer/rational

• range of values

• signed/unsigned

• precision

Literals

often need ‘type conversion’

Converting Floating Point to Integer

truncate the decimal point DON’T ROUND

Scopes

variables need to be in the right scope to be visible where they are needed

Local Scope

created when it’s declared and automatically destroyed when the function containing it ends

Global Scope

visible to the whole file

try not to use ad they take up too much memory

Variable Rules

• must be declared before use

• generally declared ‘close’ to where you need to use them

• should be initialised with some value before use

  • if you don’t you will be given a random number, different every time the program is run

Accessing Data at other Scopes

• don’t use global variables

• pass data using using parameters to functions

• return results using ‘return’ so functions evaluate to something

  • often assign the result of a function call into a variable to use later