Code: Ruby

Symbols & Hash Keys

:name literals, key: value, and hash rockets

String Interpolation

Pound-brace interpolation and squiggly heredocs

Safe Navigation & Defaults

&., ||=, and ternary conditionals

Ranges & Splats

Two-dot ranges, *args, **opts, and &:method

Checkpoint: Symbol Fluency

Blocks, symbols, and interpolation in one longer drill

Keywords

Reserved words

Declarations

Variables and constants

Classes & Modules

attr_reader, initialize, and namespacing

Guard Clauses & Modifiers

Trailing if/unless the Ruby way

Idiomatic Patterns

One-liners Rubyists love

Enumerable Chains

each_with_object, zip, tally, and friends

Checkpoint: Keywords & Idioms

An Enumerable class mixing this module's material

Control Flow

Idiomatic branching

Functions & Methods

Small complete methods

Struct & Comparable

Value objects with the spaceship operator

Exceptions & Retries

begin/rescue/retry/ensure done properly

File & JSON I/O

Reading, parsing, and writing settings

Realistic Snippet

CSV sales report

Module Mixins

Sharing behavior with include

Checkpoint: Real Snippets

Structs, grouping, and formatting in one pass

Speed Run: Config Loader

A key=value parser typed end to end without stopping

Speed Run: Enumerable Pipeline

Select-sort-sum chains at full pace

Speed Run: CLI Options

OptionParser flags and banners

Speed Run: Word Frequencies

scan, tally, and sort_by in a tight loop

Speed Run: Minitest Suite

A slugify method plus its tests

Checkpoint: Sustained Speed

An event-latency report typed in one continuous run

Assessment Sim 1: Task List Program

A complete two-class program with Enumerable

Assessment Sim 2: Reading Stats

A full ARGF-to-summary program

Assessment Sim 3: RPN Calculator

A complete stack evaluator with error paths

Assessment Sim 4: Inventory Ledger

A full stock-movement program with rejections

Checkpoint: Ruby Mastery Final

A ranked traffic report -- the course's graded final