2.2 Programming Techniques

2.2 Programming Techniques

1. Programming Fundermentals

   • Variables
     • Variables are named locations in memory that are used to store values that can change
   • Constants
     • Constants are named locations in memory that are used to store values that do not change
     • Constants are very useful for representing values that you don't want to have to re-type throughout the program,

2. Operators

   • Operators are symbols and statements that perform specific functions
   • Boolean operators
     • Boolean operators perform logic operations and always result in True and False
     • AND - evaluates to True if both operands are True; False if either operand is False
     • NOT - inverts / negates a logical value so True becomes False and False becomes True
     • OR - evaluates to True if either of the two operands are True; False if both operands are False

3. Controlling program flow

   • Building blocks of algorithms
     • Sequence - each step is executed in the order that it is written. All algorithms are made up of at least a basic sequence of instructions.
     • Selection - controls the flow of an algorithm by checking whether a condition is met or not before determining which steps should follow.
     • Iteration - controls the flow of an algorithm by repeating a set of instructions either for a fixed number of times or whilst a set condition is met.
   • Selection Struvtures
     • Selection structures allow for steps within an algorithm or program to only be followed if one or more condition has been met.
     • IF/ELSE structures run different instructions depending on whether a condition is met or not

4. Data Types

   • Real /Float Number with decimal Point
   • Integer=whole number
   • String=TEXT(series of characters)
   • Character= A single letter or symbol
   • Date/Time Date and Time in any format

5. Validation: A computer check to ensure that the data entered is sensible and reasonable. It does not check the accuracy of data.