Programming

Programming

1. Algorithm

   • Solving problems 1 step at a time
   • Processors can only process 1 instruction at a time
   • Mainly expressed as a flow chart
     • Make sure you know the symbols

2. 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)

3. 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
     • Uses language that is easier to understand by humans
     • eg Python, BASIC, Javascript
     • Has to be translated

4. Translation

   • Assembler
     • Turns assembly language into machine code
     • Can only be used in low level program
   • Compiler
     • Creates an executable file to run the program
     • Once it is compiled it doesn't need the original source code
     • Would be used for proprietary software
   • interpreter
     • Executes the source code
     • Used whencreating a program
     • Would be used on open source software

5. Control flow

   • Selection
     • IF THEN ELSE
   • Sequencing
     • The order through an algorithm
   • Iteration
     • Loops
       • WHILE or FORE

6. Datatypes

   • Variable or constant
     • Constant stays the same eg Pi
     • Variable changes during the program eg score in a game
   • integers and real numbers
     • Integar is whole number
     • Real can have decimals
   • Arrays are lists of the same data types
   • Operations are mathematical symbols eg <>+-

7. Testing

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