Unit 2.2 Programming Techniques

Unit 2.2 Programming Techniques

1. Key Words

   • Variables - Contain preset, changeable information that 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 - Join together
   • Sequencing - This allows us 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 set of conditions. Used for validation, calculation & 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, a popular human-readable programming language
   • Parameter - A special name given to a variable that is passed into a subfunction.

2. Operators - Represent the operations being performed on the data.

   • +-x/ - The 4 Basic Maths Operations
   • ^ - Exponentiation or Indices
   • MOD - Modulus, Shows the remainder
   • DIV - Quotient, shows the whole divided number

3. Data Types

   • Integers - Whole Numbers
   • Floats / Reals - Numbers with a fractional / decimal part
   • Strings - Text in a program
   • Booleans - True / False Statements

4. Two Basic Programming Constructs

   • Sequenceing
   • Selection

5. What is Casting?

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

6. Databases and Arrays

   • Arrays are ordered collections of related data where each element is accessible by an index (Number)
   • They can come as 1D or 2D
   • 1D arrays use one index whereas 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. Procedures store a set of instructions under one name whereas functions are called by assign their return value to something.

8. Subroutines are repeatable sections of code