programming fundamentals

what’s needed to create an algorithm

• To create an algorithm, the inputs, processes and outputs must be identified

What is an input?

• An input is data or information being entered/taken into a program before it is processed in the algorithm

• An input can come from a variety of sources, such as:

  • User - keyboard, mouse, controller, microphone

  • Sensors - temperature, pressure, movement

what’s a process

• A process is a doing action performed in the algorithm that transforms inputs into the desired output. The central processing unit (CPU) executes the instructions that define the process

examples of process

• Comparing two numbers

• Calculating an average

What is an output?

• An output is the result of the processing in an algorithm and usually the way a user can see if an algorithm works as intended

what are some forms of an output?

• An output can take various forms, such as:

  • Numbers - result of calculations

  • Text

  • Images

  • Actions - triggering events

what is a structure diagram?

• A structure diagram is a visual representation of problem decomposition

• A tool to show how a complex problem can be broken down into more manageable sub problems

• A planning tool for developers during the analysis of a problem

symbol for start or end in a flowchart

input/output symbol

process symbol

decision symbol

what is a syntax error

• A syntax error is an error that breaks the grammatical rules of a programming language and stops it from running

• Examples of syntax errors are:

  • Typos and spelling errors 

  • Missing or extra brackets or quotes

  • Misplaced or missing semicolons

  • Invalid variable or function names

  • Incorrect use of operators

  • Incorrectly nested loops & blocks of code

What is a logic error?

• A logic error is where the program runs/executes but produces an unexpected or undesired output

• They do not perform what the programmer intended

• Logic errors can be difficult to identify by the person who wrote the program, so one method of finding them is to use 'Trace Tables'

• Examples of logic errors are:

  • Incorrect use of operators  (< and >)

  • Logical operator confusion (AND for OR)

  • Looping one extra time

what’s a variable

• A variable is a named memory location that holds data that during the execution of a program, the data can change

• Variables can store a variety of different types of data such as numbers, text or true/false values

What is a constant?

• A constant is fixed data that during the execution of a program cannot change

• A constant can store a variety of different types of data, similar to variables

what is assignment?

• Assignment is the process of storing data in a variable or constant under a descriptive name

What is an operator?

• An operator is a symbol used to instruct a computer to perform a specific operation on one or more values

• Examples of common operators include:

  • Arithmetic

  • Comparison

  • Boolean (AND, OR and NOT)

What is an input?

• An input is a value that is read from an input device and then processed by a computer program

• Typical input devices include:

  • Keyboards - Typing text

  • Mice - Selecting item, clicking buttons

what’s an output

• An output is a value sent to an output device from a computer program

• Typical output devices include:

  • Monitor - Displaying text, images or graphics

  • Speaker - Playing audio
    

What is sequence?

• Sequence refers to lines of code which are run one line at a time

• The lines of code are run in the order that they written from the first line of code to the last line of code

• Sequence is crucial to the flow of a program, any instructions out of sequence can lead to unexpected behaviour or errors

What is selection?

• Selection is when the flow of a program is changed, depending on a set of conditions

• The outcome of this condition will then determine which lines or block of code is run next

• Selection is used for validation, calculation and making sense of a user's choices

• EG. if... then... else... statements - this is when you test conditions sequentially 

What is iteration?

• Iteration is repeating a line or a block of code using a loop

• Iteration can be:

  • count controlled - this is when the code is repeated a fixed number of times (e.g. using a for loop)

what are the 4 datatypes

• integer : whole number

• float : unwhole number

• string : letters

• boolean : true/false

What is casting?

• Casting is when you convert one data type to another data type

string manipulation ?

String manipulation is the use of programming techniques to modify analyse or extract information from a string

What is case conversion?

Case conversion is the ability to change a string from one case to another e.g. lowercase