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← Introduction to JavaScript
○What is JavaScript?○Your First JavaScript Code○Data Types○Type Checking○Inspect Values in the Console○Inspect the Queue Report○Trace a Faulty Calculation○Repair the Score Calculation✦Module Quiz
○Declaring Variables○let and const in Practice○Operators○Type Conversion○Group and Convert Expense Inputs○Calculate the Event Expense Total○Track a Changing Points Tally○Adjust a Ticket Price✦Module Quiz
○Conditionals○Demo: Combined Conditions Before FizzBuzz○Challenge: FizzBuzz Announcer○Switch Statement○Demo: Switch a Venue Sign○Challenge: Power Loadout○For Loops○While Loop○Break and Continue○Demo: Stop a Ticket Scan○Challenge: Number Guess Referee○Demo: Rainfall Routing Walkthrough○Exercise: Score Batch Report✦Module Quiz
○Defining Functions○Arrow Functions○Scope○Closures○Project - Calculator○Function Expressions○Demo: Ticket Pricing Walkthrough○Exercise: Shipping Labels with Defaults○Demo: Seat Ledger Closure Walkthrough○Exercise: Private Budget Ledger✦Module Quiz
○Arrays○Demo: Student Scoreboard○Challenge: Student Course Scoreboard○Array Mutation Methods○Array Slice and Concat○Array Iteration Methods○Multidimensional Arrays○Destructuring○Array Reverse and Sort○Array Fill○Array Find and Includes○Array Flat and FlatMap○Array Reduce, Some, and Every○Demo: Charging Rack Restock Report○Exercise: Pantry Restock Plan✦Module Quiz
○Object Key-Value Pairs○Student Course Record○Object Methods and Destructuring○Map and Set Collections●Playlist Lookup○Number and BigInt Boundaries○Ticket Ledger○JSON○Math and Date○Date Basics○Demo: Supply Bin Audit○Exercise: Volunteer Shift Audit○Demo: Workshop Attendance Feed○Exercise: Parcel Scan Feed✦Module Quiz
○String Methods○Template Literals○Regular Expressions○Demo: Build a Reminder with Template Literals○Exercise: Format Pantry Pickup Messages○Demo: Validate a Time Slot with Regex○Exercise: Validate Storage Shelf Labels✦Module Quiz
○Higher-Order Functions○Callbacks○map, filter, and reduce○Demo: Student Register with map○Challenge: Student Register○Recursion○Project - Data Transform Pipeline○Demo: Handle an Error-First Callback○Exercise: Report Seat Reservation Results○Demo: Summarize Completed Bike Rides○Exercise: Summarize Delivered Parcels✦Module Quiz
○Demo: A notebook object○OOP Introduction○Demo: Independent workshop passes○Classes○Demo: An inherited notice○Inheritance○Demo: A private seat counter○Encapsulation○Demo: Equipment desk checkout○Project: Library Checkout✦Module Quiz
○Demo: Callback Timing○Exercise: Asynchronous JavaScript○Demo: Promise Rehearsal○Exercise: Promises and Async Await○Demo: Offline API Coordination○Exercise: Async API Simulation○Demo: Partial Results Bulletin○Project: Resilient Awards Feed○Demo: Retry a Local Delivery○Project: Reliable Score Delivery✦Module Quiz

Playlist Lookup

The walkthrough used badges and tour cities. Now build a separate playlist tool. Keep durations in a Map so a title can find its duration, and keep artists in a Set so repeats disappear.

Worked example

A map retrieves a duration by key while a set removes duplicate categories:

javascript
const readings = new Map([["Poem", 4]]);
const genres = new Set(["spoken", "spoken", "music"]);
console.log(readings.get("Poem"), genres.size); // 4 2

Your Task

  1. Create a songDurations Map with the key-value entries "Orbit" → 203 and "Glow" → 187.
  2. Create a featuredArtists Set containing "Nova", "Kai", and a second "Nova" entry.
  3. Define playlistSummary(durations, artists) that returns the duration for "Orbit", a pipe, and the number of unique artists.
  4. Print this exact double-quoted text with console.log(): "203 | 2".
Hint 1
1 / 2
HINT 1

Create a Map with nested [key, value] pairs.

HINT 2

A Set automatically ignores a repeated value.

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