Paper 2 Computational Thinking

Paper 2 Computational Thinking

1. Variables

   • Locations in memory
   • Store a single item
   • Can change during the running of a program
   • Should have meaningful names for ease of human understanding
     • Names can have no spaces or start with a number

2. Data Storage & Organisation

   • Constants
     • Like variables but their value doesn't change
       • eg. pi = 3.14 VAT = 20
   • Array
     • Stores multiple items
       • Uses [square brackets]
         • Items, are, separated, by commas
           • Items must be of the same data type
             • The index number identifies the position of an item in an array
               • eg. [0] identifies the 1st item in the list
               • [-1] identifies the last item
               • A part of an array can be accessed using a slice. eg. [3:6]
     • 2D array
       • A list of lists
         • Also must be of same data type
           • [[1,2,3], [7,8,4], [12,1,14]]
     • A list
   • Database
     • A structured store of data
       • More efficient for searching
       • Removes data redundancy
         • Data redundancy = data entered twice
           • Reduce human entry to reduce errors
     • Table
       • A collection of records about an entity
         • Entity = thing!
         • Record
           • A row in a table that holds data about one entity
             • eg. A record about 1 student
         • eg. A table of students