Programming 2

Programming 2

1. Control Flow

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

2. Algorithm

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

3. Testing

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

4. Data Types

   • Variable or constant
     • Constant stays the same e.g Pi
     • Variable changes during the program e.g score in a game
   • Operations are mathematical symbols e.g < > + -
   • Arrays are lists of the same data types
   • Integers and real number
     • Integer is a whole number
     • Real number(sometimes called float) can have decimal places

5. Pseudocode

   • Used for planning algorithm
   • Should allow a programmer to write it in any language
   • Key words written in capital letter (e.g INPUT, IF , WHILE)

6. High level/low level programming

   • High level programming
     • E.g Python, BASIC, javascript
     • Uses language that is easier to understand by humans
     • Has to be translated
   • Low level programming
     • Machine code
       • Binary codes for each instruction and register location
     • Assembly code
       • Written as each instruction and register location
       • Codes specific to a type of processor
       • E,g INP, LDA, OUT

7. Translation

   • Assembler
     • Turns accembly language into machine code
     • Can only be used in low level programming
   • Compiler
     • Creates an executable file to run the program
     • Once it is complied it doesn't need the original source code
     • Would be used for proprietary software
   • Interpreter
     • Would be used on open source sofware
     • Used when creating a program
     • Executes the source code directly