Data Structures
📋 What it is
A data structure organises data so it's easy to use — a list keeps order, a dictionary maps keys to values.
🗣️ Coach says
Data STRUCTURES are ways to organise information. A LIST (or array) keeps items in order, like a to-do list. A DICTIONARY (or map) pairs keys with values, like a real dictionary pairing words with meanings. Choosing the right structure makes your program faster and your code clearer.
🧠 Memory hook
List = ordered items. Dictionary = key→value pairs. Pick the structure that fits.
😂 Giggle
Why did the variable feel insecure?
Because its value kept changing and it had no constants in its life!
😲 Whoa!
A dictionary/hash-map can find any item almost instantly no matter how many it holds — which is how a search engine looks something up among billions of pages in a flash.
✅ Quick check: What is the difference between a list and a dictionary?
Say your answer out loud first — then reveal.
A list stores items in order (accessed by position); a dictionary maps keys to values (accessed by key, like word→meaning).
Lists are ordered sequences; dictionaries are key-value lookups.
🧪 Try it! (2 minutes)
Decide which structure fits: a class register (list) vs matching each student to their grade (dictionary).