2.2 Problem solving and programming

sequence branching iteration

when code is executed line-by-line, from top to bottom

when a particular block of code is met if a specific condition is met examples are if and else statements

blocks of code which loop can be either: count controlled- blocks of code looping over a certain number of times condition controlled- blocks of code looping until a specific condition is met examples are DO, WHILE, FOR loops

When a subroutine calls upon itself during its execution -continues until a stopping condition is met

-code can be represented in fewer number of lines -easier to express some functions recursively e.g. factorial

-risk of stack overflow if memory runs out -difficult to trace

-variables can be defined with a global or local scope -a scope is the section of code where the variable can be accessed

variables which can only be accessed within the subroutine where they were defined

variables which can be accessed through the whole program

+won’t affect other sections of code +deleted once subroutine ends so doesn’t take up lots of memory +multiple local variables with same names but in different subroutines can exist -need to keep declaring in different sections of code if needed there

+useful for values that need to be used by multiple parts of the program -if changed, it will affect other areas of code where it has been called upon -can unintentionally edit it -not deleted until program terminates so requires more memory

a technique used to split large/complex programs into smaller, self-contained modules

-easier to divide tasks between a team and manage projects -simplifies the process of testing and maintenance (each component can be tested individually -improves reusability of components

-technique to modularise programs -problem is broken down into subproblems until each is is represented into individual, self-contained modules which perform a specific task -modules form blocks of code called subroutines

-blocks of code which perform a specific task -functions return a value -can pass parameters by value or by reference

-blocks of code which perform a specific tasks -procedures output values -can pass parameters by value or by reference

-address of parameter is given to the subroutine -value of parameter will be updated at the given address -changes the original data stored

-a copy of the value is passed to the subroutine and discarded at the end -the original value stored is unaffected

integrated development environment -provides a set of tools to make it easier for programmers to write, develop and bug code

-stepping (executes line by line to see how each line effects program) -variable watch (observes the contents of variable and how they change in real time through execution) -debugging tools (provides errors in lines during run-time) -autocompletion -syntax highlighting -breakpoints

a template for an object -defines state and behaviour for an object

state- using attributes behaviour- methods

a particular instance of a class