The execution of statements one
after another. This usually forms
the bulk of the code in any program
Selection
Selection is where the flow through a
program is interrupted and control is passed
to another point in the program. The
decision is based on a Boolean expression.
Iteration
Controlled by the state of a
Boolean expression, a
section of code is repeated.
Recursion
When a procedure or function calls itself
This can be another way to produce iteration
Global & Local Variables
Global Variables
Declared or initisialised
outside any sub programs;
functions or procedures
Accessible to code written
anywhere in the program
Can be accidentally
changed
Local Variables
Declared inside
a subprogram
Only accessible within the
sub program it is declared in
Branch
BRA (Branch always)
This is a jump instruction
that is always executed
BRP (Branch if positive)
This is a jump instruction that occurs when
the value in the accumulator is positive
Subprograms
Functions
An algorithm that takes an input and
produces an output for each input
Defining a function requirments
A Function Name
Any parameters needed by the function; that is,
the data that must be fed into the function
The output - usually one output but
there can be zero or many outputs
The processing code itself
Returns a value
Must be written as part of an equation
Procedures
Dosen't return a value
Does not need to be written as part of an equation
Exact definitions of functions and
procedures are slightly diffirent
depending on which language you use
Parameter Passing
By reference (By Ref)
The function is given the actual memory address of
where the data for the variable is stored
Any changes to the variable in
the function are permenant
By value (By Val)
A copy of the original data is passed the
function and any changes made are lost as
soon as the function is no longer in use
The IDE (Integrated development environment)
A text editor used for
writing source code
Facilities for
automating the build
A debugger
Features to help with code writing, such
as pretty printing and code completion