Algorithmic constructs

Algorithmic constructs

1. Sequence

   • A sequence is a number of instructions that are processed one after the other.
   • Each step is an instruction to be performed. Sequencing is the order in which the steps are carried out.

2. Assignment

   • Assignment is used to store the value of an expression into a variable.
   • In programming, this is exactly the same idea, except computers can remember anything not just numbers. Additionally, the variables are generally given more meaningful names that relate to the data they contain e.g. studentName = "Tom".

3. Selection and Condition

   • A selection statement uses a condition to select, or determine, the next line of the program that is to be executed.

4. Iteration

   • While Loop
     • In comparison, a WHILE loop is used to repeat while a condition is true or false. In this example, the WHILE loop will loop until a pile of items are all counted:
   • For Loop
     • Iteration is also called repetition and is used when something is repeated over and over again, so anything where the program goes round in a loop.
     • NOTE: A FOR loop is used when it is known exactly how many times to go round the loop

5. Modularisation

   • Modularisation is used to reduce the complexity of a system by deconstructing it into independent units or modules.
   • We use the term "function" as that is what they are called in most of the popular programming languages of today. Functions are important because they allow us to take large complicated programs and divide them into smaller manageable pieces that are more easily maintained.