Programming · Both
Programming Constructs
Almost every program is built from sequence, selection and iteration. Know when to use each.
The three constructs
• **Sequence** – steps in order
• **Selection** – IF / ELSE decisions
• **Iteration** – loops (count-controlled FOR; condition-controlled WHILE)
Variables store values that can change. Use meaningful names.
Operators
• Arithmetic: + − * / MOD DIV
• Comparison: = ≠ < > ≤ ≥
• Boolean: AND OR NOT
Comparison operators drive selection and loop conditions.
Worked example
When is a WHILE loop better than FOR?
Solution: When you do not know in advance how many times to repeat – you loop until a condition becomes false.
Practice questions
1. Name the three basic programming constructs.
2. FOR vs WHILE?