programming

programming

1. algorithms

   • solving problems 1 step at a time
   • processors can only process 1 instruction at a time
   • mainly expressed as a flow chart
     • symbols

2. pseudocode

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

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 a human
   • eg Python,Basic,javascript

4. translation

   • assembler
     • only can be used in low level programming
     • turns assembly language into machine code
     • interpreter
       • would be used for proprietary software
       • executes the source code directly
       • used when creating a 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

5. control flow

   • sequencing
     • the order through an algorithm
   • selection
     • IF THEN ELSE statements
   • iteration
     • loop
       • WHILE or FOR

6. data types

   • variable or constant
     • variable changes during the program eg score in a game
     • constant stays the same
   • integers and real numbers
     • integer is a whole number
     • real sometimes called float can have decimal places
     • arrays are lists of the same data types
   • operations are mathematical symbols eg <>+-

7. testing

   • syntax error
     • not a correct command for the coding language being used
   • run time error
     • an error in the program eg stuck in a loop
   • logical error
     • Human error with the construction of the algorithm