JavaScript practice
You consolidate basic JavaScript with short, real problems and combine what you learned in a task you solve on your own in each section.
Level 101 · 15 lessons · 12 practice labs
Lessons
Numbers and text
- Running scripts with Node
- A temperature converter
- Counting the words in a text
- Does it read the same backwards
- Checking password rules
- Short task: a summary report of a text file
Arrays and objects
- A shopping cart with filter, map and reduce
- Grouping records
- Sorting an array of objects by several fields
- Removing duplicates with Set
- Reading and summarising a JSON file
- Short task: a monthly summary from sales data
Small programs
- A to-do list on the command line
- A quiz game
- Capstone: a library loan tracker
Practice labs
- Find the longest word in a paragraph: In a Node script, print the longest word in a given paragraph and its length.
- Build a word frequency table: Count the words in a customer-reviews file ignoring case and punctuation, and list the ten most frequent.
- Validate username rules: Check a list of usernames against length, allowed-character and banned-word rules and print why each one fails.
- Filter out sold-out items: Remove sold-out items from Lale Çiçekçilik's product array and list the names of the rest.
- Sort a league table by two fields: Write a function that sorts a school tournament's results by points, then by goal difference on ties.
- Merge two branches' customer lists: Merge customers with the same email from two branches' lists and add up their spending.
- Get the daily revenue from a JSON file: Read a cafeteria's daily sales JSON file and print the total revenue.
- Report expenses by category: Group a shop's expense records by category and print each group's total and share as a table.
- Clean and summarise orders with missing fields: Clean an orders file where some records lack a date or amount, then produce a weekly summary and the number of skipped records.
- Write a command-line calculator: Write a script that takes two numbers and an operator from the command line, prints the result and warns on bad input.
- Keep appointments in a JSON file: Write a command-line tool for a barber that adds, lists and deletes appointments and keeps them in a JSON file.
- Build a word-guessing game in the terminal: Write a terminal game that picks a random word, lets the player guess letters and tracks lives and score.
About this course
You consolidate basic JavaScript with short, real problems and combine what you learned in a task you solve on your own in each section.
What you will learn
- Numbers and text
- Arrays and objects
- Small programs
Prerequisites
No prior knowledge is needed; the course starts from zero.
Lab environment
Lessons run in your own Kali Linux terminal that opens in the browser. Nothing to install; the lab starts clean in every lesson.
Frequently asked questions
- Is this course right for my level?
- The course is at beginner level; every term is explained where it first appears.
- Is there anything to install?
- No. Every lesson runs in your own lab environment that opens in the browser.
- How do lessons work?
- Each lesson has 8 to 10 steps and a short quiz. Early steps show the command to type, later steps give less help; if two attempts fail, the solution opens.
- Can I try it for free?
- Yes. The first three lessons of every course are free.