Programming

Programming

1. control flow

   • Literation
     • Loops
       • WHILE or FOR
   • Selection
     • IF THEN ELSE
   • Sequencing
     • The order through an algorithm

2. Algorithms

   • Solving problems 1 steps at a time
   • Processor can only process 1 instructions at a time
   • Mainly expressed as a flow chart
     • Make sure you know the symbols

3. Data types

   • Variable or constant
     • Constant stays the same eg pi
     • Variable changes the program eg score in the game
   • Operation are mathematical symbol eg <> + -
   • Arrays are lists of the same data types
   • Integers and real numbers
     • Integer is a whole number
     • Real (sometimes called float) can have decimal places

4. Pseudocode

   • Used for planning algorithms
   • Should allow a programmer to write it in any language
   • Key words written in capital letters (eg INPUT, IF, WHILE)

5. High level / low level programming

   • Low level is understood by the processor
     • Machine code
       • Binary codes for each instruction and register location
     • Assembly language
       • codes specific to a type of processor
       • eg INP, LDA, OUT
   • High level has to be translated
     • eg Python, BASIC, Javascript
     • Has to be translated
     • Uses language that is easier to understand by humans

6. Translation

   • Interpreter
     • Would be used on open source software
     • Used when creating a program
     • executes the source code directly
   • Compiler
     • Would be used for proprieary software
     • Once it is compiled it doesn't need the original source code
     • creates an executable file to run the program
   • Assembler
     • Turns assembly language into machine code
     • Only can use in low level programming

7. Testing

   • Logical error
     • human error with the construction of the algorithm
   • Run-time error
     • An error in the program eg stuck in a loop
   • Syntax error
     • Not a correct command for the coding language being used