Data Structures, Algorithms & the Web

1. № 01 · Getting oriented

   Cheat-sheet for this module
   • From basics to structures5 min read

2. № 02 · Collections and data types

   Cheat-sheet for this module
   • Tuples and immutability7 min read
   • Dictionaries: key and value8 min read
   • Sets and set operations7 min read
   • Reading and writing files8 min read

3. № 03 · Linear data structures

   Cheat-sheet for this module
   • Abstract data types6 min read
   • Stacks: last in, first out7 min read
   • Queues: first in, first out7 min read
   Checkpoint: show what you can do

   You should be able to

   • • Describe a collection by the operations it promises, not by how it stores things
   • • Tell a guarantee the contract makes from a behaviour that merely happens to be true in one implementation
   • • Predict which of your own code survives when the implementation is swapped underneath it, and say why
   • • Name what a contract is silent about, including what it costs to run
   • • Add a missing promise to a contract in one sentence

   Take a data structure you already use, in Python or anywhere else. Write down two things it promises you and one thing you rely on that it never actually promised. Then say what would break if that second thing stopped being true tomorrow.

   Evidence: Two promises, one unpromised assumption, and the consequence of losing it.

4. № 04 · Thinking about efficiency

   Cheat-sheet for this module
   • Big-O: measuring how code scales8 min read
   • Comparing two approaches7 min read
   • Sorting a list8 min read
   Checkpoint: show what you can do

   You should be able to

   • • Estimate how an approach grows by counting the loops that touch the data, including hidden ones
   • • Choose between two working approaches for a stated job at a stated size
   • • Revise that choice when the size or the requirement changes, and say why in one sentence
   • • State where the Big-O model stops being reliable

   Take a piece of code you have written that checks whether something is in a list. Say what its growth shape is, what you would change if the data became a hundred times larger, and what that change would cost.

   Evidence: One sentence naming a growth shape and the cost you would accept to change it.

   Need a hint?

   A membership test on a list is a hidden loop. Inside your own loop, that is a loop within a loop.

5. № 05 · Object-oriented programming

   Cheat-sheet for this module
   • Classes and objects8 min read
   • Attributes and methods8 min read
   • Inheritance8 min read
   • Polymorphism7 min read
   • Encapsulation and abstraction8 min read
   Checkpoint: show what you can do

   You should be able to

   • • Model a small domain with classes, objects, attributes and methods
   • • Modify one object's state without accidentally changing another
   • • Extend or substitute behaviour while keeping the code that uses the objects stable
   • • Debug mismatched constructors, attributes and method contracts before the capstone

   Take one class from your practice. Add a new kind of object or one changed behaviour, run the old using code unchanged, and explain the first mismatch you had to debug.

   Evidence: Working code plus one sentence connecting the fix to the object's contract.

6. № 06 · A first taste of the web

   Cheat-sheet for this module
   • HTML: the structure of a page7 min read
   • Text, images and links7 min read
   • CSS: styling your page8 min read
   • JavaScript basics8 min read
   • The DOM: making pages interactive8 min read
   Checkpoint: show what you can do

   You should be able to

   • • Create a small semantic page, style it and change it through one user action
   • • Trace a browser interaction from event to JavaScript to a visible DOM change
   • • Use the console and exact name matching to debug a page that does not respond
   • • Keep the page small enough to become the capstone's presentation layer

   Build the smallest page that shows three items and changes one visible state on a click. Then deliberately break one id or function name, use the console to locate it, repair it and describe the signal that led you to the fix.

   Evidence: A working HTML/CSS/JavaScript page plus one observed error and its repair.

7. № 07 · Capstone

   Cheat-sheet for this module
   • Capstone: build your project25 min read
   • Presenting your project5 min read

This course was developed by alphaPlan Center from programs delivered in partnership with the American Corners network. Who made what