Unit 2.2

Unit 2.2

1. Key Words

   • Variables
     • Contain preset changeable information
       • Can be altered throughout the code
   • Constant
     • Contains fixed information that is the same whilst the code is running
   • Operators
     • They represent the operations being performed on the data
   • Concatenate
     • Joining things together
   • Sequencing
     • This allows the user to solve complex tasks through a number of simple steps
       • A step by step solution
   • Selection
     • Changes the flow of a program, depending on a certain conditions
       • Used for validation, calculation and making sense of a user's choices
   • Iteration
     • Repeating things over and over
   • Stepping
     • Skipping things in an iteration
   • EOF
     • End of File
   • EOL
     • End of Line
   • SQL
     • Standard Query Language
       • Human readable programming language

2. Operators

   • The 4 Basic Maths Operations
     • +
     • -
     • ÷
     • x
   • ^
     • Exponentiation or Indices
   • MOD
     • Modulus
       • Shows the remainder
   • DIV
     • Quotient
       • Shows the whole divided number
   • Represent the operations being performed on the data

3. Data Types

   • Integers
     • Whole Numbers
   • Floats or Reals
     • Numbers with a fractional or decimal part
   • Strings
     • Text in a program
   • Boolean
     • True and False Statements

4. Two Basic Programming Constructs

   • Sequencing
   • Selection

5. Casting

   • Change how a variables data type is interpreted
   • str(123)
     • Turns 123 into a string
   • int("123)
     • Turns "123" into an integer

6. Arrays and Databases

   • 1D or 2D
     • Arrays are ordered collections of related data
       • Each element is accessible by an index (Number)
     • 1D arrays use one index
       • 2D arrays uses 2 indexes
       • Similar to co-ordinates
     • 2D arrays use numeric index instead of names
     • Record
       • A specific row of information referring to one specific entity
     • Fields
       • A single cell in the database

7. Subroutines

   • Repeatable sections of code