Coding Challenges
Sharpen your instincts with quick challenges, keep your streak alive, and climb the leaderboard.
JavaScript
Available Products
Use JavaScript filter() to return only available product objects, keeping their original order and leaving the source array unchanged.
JavaScript
Available Seats
Write a JavaScript function that accepts an array of seat states, loops through it, and returns the number of seats still available.
Python
Available Seats in Python
Write a Python function that accepts a list of seat states, loops through it, and returns the number of seats still available.
JavaScript
Battery Warning
Use a JavaScript if statement to detect a low battery level and print a clear warning when the charge drops below 20 percent.
Python
Battery Warning in Python
Use a Python if statement to check a battery level and print a warning only when the provided value falls below the required threshold.
React
Build a Character Limit Textarea
Build a typed React textarea that enforces a configurable character limit, reports the remaining count, and sends each accepted value upstream.
Featuring
JJason Torres
HTML & CSS
Build a Coffee Shop Menu
Style a hand-printed coffee shop menu with a centered card, aligned item prices, separators, and a featured drink treatment.
JavaScript
Build a Field Notes Checklist
Add delegated checklist toggles, persistent status filters, and accessible progress updates to a field journal, including an accurate empty state.
HTML & CSS
Build a Flexbox Navigation Bar
Use CSS Flexbox to align a semantic site header, place the brand and navigation apart, and space the navigation links in one clear row.
TypeScript
Build a Generic Result Wrapper
Build a generic TypeScript Result type and helper functions that preserve each success value's type while representing failures safely.
JavaScript
Build a Live Festival Pass
Complete a festival pass input handler that trims the visitor's name, updates the badge instantly, and shows an accurate 20-character count.
HTML & CSS
Build a Museum Exhibit Timeline
Style a museum exhibit timeline with a copper spine, aligned year badges, archival cards, and a distinct treatment for the featured milestone.
JavaScript
Build a Notification Inbox
Use one delegated click handler to mark inbox items as read, update each button and row, and recalculate the remaining unread total.
Python
Build a Python Slugify Utility
Write a Python slugify function that lowercases words, preserves digits, collapses punctuation into single hyphens, and handles empty input.
React
Build a Recipe Serving Scaler
Build a React recipe scaler that updates ingredient amounts from serving state, respects the 1 to 8 limits, and restores the original recipe.
HTML & CSS
Build a Responsive Product Grid
Turn a stacked product list into a three-column CSS Grid with consistent gaps, then collapse it to one column on screens up to 700px.
HTML & CSS
Build a Semantic FAQ Card
Build a native FAQ disclosure with semantic details and summary elements, then style the question and answer as a compact dark card.
React
Build a Team Member Card
Complete a reusable React team member card that reads name, role, and online status from props while rendering both example members.
JavaScript
Build a Ticket Quantity Stepper
Wire a ticket quantity stepper that stays between zero and eight, updates the total and summary, and disables controls at the correct limits.
TypeScript
Build a TypeScript Slugify Utility
Write a TypeScript slugify function that lowercases words, preserves digits, collapses punctuation into single hyphens, and handles empty input.
Featuring
JJason TorresHTML & CSS
Build a Workshop Signup Form
Build an accessible workshop signup form with connected labels, appropriate controls, and native required-field validation, using only HTML.
JavaScript
Build an Async Task Pool
Build a JavaScript task pool that limits concurrent promises, starts queued work as slots open, preserves result order, and rejects on failure.
HTML & CSS
Build an Editorial Pull Quote
Add a semantic editorial pull quote with figure, blockquote, caption, and citation markup, then lay it out with CSS Grid and a decorative mark.
JavaScript
Build an Interactive Metro Route Planner
Create a two-step DOM interaction that selects metro endpoints, highlights the route, calculates stops, and resets the planner.
JavaScript
Convert a Promise Chain to async/await
Refactor a working JavaScript Promise chain into an async function that awaits user and post data before returning one dashboard object.
JavaScript
Delivery Speed
Build a JavaScript else if chain that classifies delivery speed as Express, Priority, or Standard from the provided number of days.
Python
Delivery Speed in Python
Classify a Python delivery estimate with if, elif, and else branches that cover express, priority, and standard arrival ranges.
JavaScript
Find a User
Build a JavaScript function with find() that returns the user matching a requested ID, or null when no user has that ID.
JavaScript
Find the First Available Seat
Use Array.find() to return the first seat whose availability is exactly true, or null when the list contains no open seats.
Python
Find the First Available Seat in Python
Use Python's next() with a generator to return the first truly available seat label, or None when the list has no open seats.
JavaScript
Find the Low Stock Products
Write a JavaScript function that returns low-stock product names in source order, including items exactly at the requested inventory limit.
Python
Find the Low Stock Products in Python
Write a Python function that returns low-stock product names in their original order, including items exactly at the supplied limit.
JavaScript
Fix the Async Retry Helper
Repair an async retry helper so it stops at the first successful result, respects the attempt limit, and throws the final failure.
JavaScript
Fix the Catalog Query Helper
Repair a catalog query helper so filtering, numeric sorting, pagination, and result metadata work correctly without mutating the product list.
HTML & CSS
Fix the Div Soup Page
Turn a div-only page into meaningful HTML with header, navigation, list, heading, main, and footer elements that clarify its structure.
React
Fix the Mutating Todo State
Fix a React todo toggle by updating state immutably, changing only the selected item while keeping counts, styles, and repeated clicks in sync.
Featuring
JJason TorresReact
Fix the Product Search Filter
Repair a React product search so the input updates component state and filters product names immediately without case sensitivity.
Python
Fix the Python Shopping Cart Total
Fix a Python shopping cart function so it multiplies every item's price by its quantity, totals every line, and handles an empty cart.
JavaScript
Fix the Shopping Cart Total
Fix a JavaScript cart total function so it multiplies every item's price by its quantity, includes all lines, and returns zero for an empty cart.
JavaScript
Free Shipping
Combine JavaScript comparison and logical operators to decide when an order qualifies for free shipping based on total and membership.
Python
Free Shipping in Python
Combine Python logical operators to award free shipping for qualifying totals or member orders while handling every other order.
JavaScript
Fuel Gauge
Practice a JavaScript while loop by increasing a fuel gauge in fixed steps until the tank reaches 100 percent and launch is ready.
Python
Fuel Gauge in Python
Use a Python while loop that prints the remaining fuel, changes its state each time, stops at zero, and prints an empty warning.
JavaScript
Game Start Countdown
Use a descending JavaScript for loop to count from five to one, then print a final message that starts the game for waiting players.
Python
Game Start Countdown in Python
Use a descending Python for loop with range to print a countdown from the provided starting number, followed by a clear launch message.
JavaScript
Handle a Rejected Request
Use JavaScript async/await with try and catch to return a clear success or error result from a deterministic profile request.
TypeScript
Handle Optional Profile Fields
Handle optional TypeScript profile fields with nullish fallbacks so complete and partial profiles produce clear readable summaries.
JavaScript
Highest Score
Build a JavaScript function that loops through a score array and returns the highest value without sorting or using higher order methods.
Python
Highest Score in Python
Build a Python function that loops through a score list and returns the highest value without sorting or using built-in maximum helpers.
JavaScript
Inventory Report
Calculate total inventory value in JavaScript by looping through product objects, multiplying price by quantity, and returning the total.
HTML & CSS
Mark Up a Ramen Recipe
Replace paragraph-only recipe content with description, unordered, ordered, and nested lists that give each section the right HTML structure.
JavaScript
Merge Settings
Merge default and user JavaScript settings with object spread syntax, preserve both original objects, and return the combined settings.
JavaScript
Mission Clearance
Combine role, account status, two factor security, and clearance level in JavaScript to select the correct mission access result.
Python
Mission Clearance in Python
Combine several Python boolean checks in an ordered conditional chain to assign full, edit, read only, or denied mission access.
TypeScript
Model a Product Object
Define a TypeScript product object type with required primitive fields so the provided formatter and sample catalog compile safely.
TypeScript
Model Deployment Events with TypeScript
Model deployment events with a TypeScript discriminated union so status checks narrow every variant to its required fields safely.
TypeScript
Narrow a Search Result
Use TypeScript union narrowing with typeof to format text and numeric search results safely without weakening the declared types.
JavaScript
Obstacle Course
Control a JavaScript loop with continue and break to skip blocked course levels and stop when the final checkpoint is reached.
Python
Obstacle Course in Python
Use Python continue and break inside a loop to skip one checkpoint, stop at the finish, and avoid processing later entries.
JavaScript
Order Readiness
Combine JavaScript some() and every() to decide whether an order has no backorders and every requested quantity is valid.
JavaScript
Order Total
Combine functions, arrays, loops, and conditionals in JavaScript to total an order, apply a qualifying discount, and return the final price.
Python
Order Total in Python
Combine functions, lists, loops, and conditionals in Python to total an order, apply a qualifying discount, and return the final price.
JavaScript
Pack the Backpack
Use JavaScript push() to add two essential supplies to a backpack array, then report the completed packing list and its new length.
Python
Pack the Backpack in Python
Use Python append() to add two essential supplies to a backpack list, then print the completed packing list and its new length.
JavaScript
Passing Scores
Loop through JavaScript scores, identify every passing result, and maintain an accurate count without changing the original array.
Python
Passing Scores in Python
Combine a Python for loop, conditional check, and accumulator to count how many scores meet or exceed the passing threshold.
JavaScript
Personal Greeting
Write a JavaScript function that accepts a name, returns a personalized greeting, and prints the result from a call with the provided value.
Python
Personal Greeting in Python
Write a Python function that accepts a name, returns a personalized greeting, and prints the result from a call with the provided value.
JavaScript
Player Profile
Create a JavaScript player object with three properties, then read its name and level to print a clear profile summary in the Output panel.
Python
Player Profile in Python
Create a Python player dictionary with name, level, and role values, then read its keys to print a clear profile summary.
JavaScript
Priority Queue
Manage a JavaScript support queue with shift() and unshift(), recording the served customer before placing an urgent customer at the front.
JavaScript
Product Label
Build a JavaScript function that accepts a product object and returns a formatted label using its name and price properties.
Python
Product Label in Python
Build a Python function that accepts a product dictionary and returns a formatted label using its stored name and price values.
JavaScript
Product Labels
Build a JavaScript function that uses map() to turn product objects into formatted price labels while preserving their original order.
React
Refactor the Notification Settings
Refactor repeated React notification rows into one reusable component while keeping state in the parent and preserving every toggle and reset behavior.
JavaScript
Remove the Last Track
Use JavaScript pop() to remove the final track from a playlist, capture the returned value, and print both the removed track and remaining songs.
Python
Remove the Last Track in Python
Use Python pop() to remove the final track from a playlist, save the returned song, and print both the removed track and remaining list.
JavaScript
Repair the Inventory
Repair a JavaScript inventory with splice() by replacing one unavailable item with two new supplies, then report what was removed and the final list.
JavaScript
Resolve a Delayed Message
Complete a JavaScript Promise that resolves a delayed message, then run the program to confirm the value appears after the timer finishes.
Python
Reverse a List in Python
Reverse a Python list by hand with a loop, return a new list, and leave the original order unchanged without using built-in shortcuts.
Python
Route Endpoints in Python
Read values from a Python list by positive and negative index, then print the first and last destinations from the provided route.
JavaScript
Run Independent Tasks with Promise.all
Run three independent JavaScript data requests concurrently with Promise.all, then return their results together in one dashboard object.
JavaScript
Secure Login
Order JavaScript conditional rules so a locked account takes priority over a correct password and produces the proper login message.
Python
Secure Login in Python
Apply prioritized Python conditional rules so an account lockout takes precedence before a correct password can grant or deny access.
JavaScript
Shipping Address
Work with a nested JavaScript customer object by updating its city and printing a complete shipping address from nested properties.
Python
Shipping Address in Python
Work with a nested Python customer dictionary by updating its city and printing a complete shipping address from nested values.
JavaScript
Shopping Cart Total
Use JavaScript reduce() to total a shopping cart by multiplying each item's price by its quantity, including an empty cart total of zero.
HTML & CSS
Style a Responsive Pricing Card with Tailwind
Style an unformatted subscription card with responsive Tailwind utilities, including a featured badge and accessible interaction states.
Featuring
JJason TorresHTML & CSS
Style an Event Card
Style a semantic HTML event card with foundational CSS spacing, borders, colors, and a clear deadline badge in the browser preview.
JavaScript
Summarize Orders by Status
Use JavaScript reduce() to group orders by dynamic status values, calculating each group's count and total without changing the source data.
Python
Summarize Orders by Status in Python
Group Python order records by dynamic status values, calculating each group's count and total without changing the input data.
JavaScript
Supply Run
Use a JavaScript for...of loop to pack every supply in array order, then report how many items were packed for the trip.
Python
Supply Run in Python
Iterate directly over a Python list of supplies and print every packed item in its original order without hardcoding the values.
JavaScript
Team Roster
Use JavaScript forEach() to print every team member in order with a clear label, practicing callback values without changing the original array.
JavaScript
Ticket Booth
Use JavaScript if and else branches to choose the correct ticket label for a child or standard admission based on the provided age.
Python
Ticket Booth in Python
Use Python if and else branches to choose the correct admission label from a visitor's age and print the resulting ticket type.
JavaScript
Ticket Price
Use a JavaScript function with parameters and conditional returns to calculate the correct ticket price from age and membership status.
Python
Ticket Price in Python
Use a Python function with parameters and conditional returns to calculate the correct ticket price from age and membership status.
JavaScript
Tip Calculator
Build a JavaScript tip calculator function that accepts a bill total and percentage, returns the tip amount, and prints the calculated result.
Python
Tip Calculator in Python
Build a Python tip calculator function that accepts a bill total and percentage, returns the tip amount, and prints the calculated result.
JavaScript
Toggle the Record Player
Complete a record player control that toggles playback, updates the button and status labels, and keeps the turntable animation in sync.
JavaScript
Treasure Grid
Search a JavaScript grid with nested loops, locate the hidden treasure marker, and report its row and column coordinates.
Python
Treasure Grid in Python
Search a two-dimensional Python grid with nested loops and report the zero-based row and column containing the treasure marker.
TypeScript
Type a Price Calculator
Add TypeScript parameter and return annotations to a price calculator so strict compilation succeeds while preserving the calculated total.
JavaScript
Update the Guest List
Update a JavaScript guest list by replacing one array item through its index, then print the corrected list without adding another guest.
Python
Update the Guest List in Python
Update a Python list item in place through its index, then print the corrected guest list without adding or removing any names.
JavaScript
Update the Scoreboard
Update an existing JavaScript scoreboard object by changing its score, adding a winner status, and printing the completed object.
Python
Update the Scoreboard in Python
Update a Python scoreboard dictionary with a new score and winner key, then print the completed game result from the stored data.
JavaScript
Weekend Schedule
Use JavaScript slice() to copy the weekend plans from a weekly schedule, then print both arrays to prove the original schedule stayed unchanged.
Python
Weekend Schedule in Python
Use Python list slicing to copy the weekend plans from a weekly schedule, then print both lists to confirm the original stays unchanged.