Paper 2

named locations that store data in which the contents can be changed during program execution

declared inside a function. They can only be accessed and used in that function.

declared outside of all the functions, they can be used throughout the whole program including inside functions.

easier to create and test

self-contained units of code that perform some well-defined purpose.

a subprogram that ALWAYS returns a single value

a subprogram that returns one or many values.

the data that is supplied to a subprogram so that they can be reused

the address of the variable is passed to the subprogram. if the variable is changed it stays changed.

a copy of the variable is passed to the subprogram. The original variable is unchanged no matter what the subprogram does.

the list needs to be sorted

works by dividing a list into two groups: sorted and unsorted. Elements are inserted one by one into their correct position in the sorted section.

represents reality by recognising what is important and blocking out other details

planning input and outputs e.g. caching

a temporary store where data and instructions or data that are likely to be needed are stored.

writing in modules to split a problem up into manageable tasks

inferring things from what you already know and understanding where decisions need to be made and their consequences

thinking about how a job might be done better if some parts were performed at the same time.

• Auto-complete • colour coding/ syntax highlighting • stepping • breakpoints • watch window • error diagnostics

recognises identifiers

identifies different features making the code easier and quicker to check

runs one line at a time to check the result, good for error checking

stops the code at set points to check the value of variables, good for error checking

tracks how variables change during the execution