Northstar Learning › Coding course

Learn TypeScript by doing

300 quests · JavaScript foundations, unions, narrowing, generics, tuples and async · strict mode

300 questions · free · no account needed · works offline once loaded

What you will cover

• Values and arithmetic
• Text and conversion
• Booleans and boundaries
• Branching
• Loops and totals
• Functions and return
• Arrays and indexing
• Mapping values
• Filtering collections
• Objects and properties
• Union types
• Narrowing unions
• Optional properties
• Generic functions
• Readonly properties
• Tuples
• Records
• Discriminated unions
• Function contracts
• Promises and async

Try some questions

Tap a question to see the answer and why.

const adults = 3;
const kids = 2;
const price = 8;
console.log((adults + kids) * price);

Play with friends

Northstar also has a group quiz: host a live room, run one on a single screen, or send a friend a challenge link.