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1. Create a TypeScript/React app with Vite.
2. Define a CounterList component:
1. Define a state variable that initializes with an empty array.
2. Render a button that adds a new number to the array that matches the current length of the array.
3. Render the list of numbers in a bulleted list.
Bonus: Inside CounterList, render another button that adds 1 to the last element of the array.
const bakeryVan = {
destination: 'bakery',
cargo: 5
}
const schoolVan = {
destination: 'school',
cargo: ['Dorothy', 'Zelda', 'Tallulah']
}
/*
type Input <T> = {
data: T | string
}
type PremiumInput <T> = Input<T> & {
price: number
}
*/
# Sections
1. JavaScript
2. TypeScript
3. Asynchronous Programming
4. Express.js
# Questions
## JavaScript (Core)
### Language fundamentals
1. What is the difference between passing a primitive value and passing an object as a function argument in JavaScript? What happens in each case when you modify the parameter inside the function?
### Execution model (call stack, event loop, task queues)
# Socket.io Chat App
## 1. Connection & Identity Registration
- Client connects with a username
- Server accepts or rejects the connection
- Server assigns a socket ID
- User is removed from state on disconnect
### Topics
export function format(value, formatter) {
const formatted = formatter(value);
return formatted;
}
function formatString (value) {
return value.toUpperCase()
}
function formatNumber(value) {
const departments = {
engineering: {
budget: 500000,
headcount: 45,
location: "Building A",
},
marketing: {
budget: 300000,
headcount: 20,
location: "Building B",
const franchises = {
theGodfather: {
book: {
year: 1969,
author: 'Puzo',
title: 'The Godfather'
},
original: {
budget: 7200000,
director: 'Coppola',
const originals = {
theGodfather: {
budget: 7200000,
director: 'Coppola',
title: 'The Godfather'
},
theHobbit: {
author: 'Tolkien',
year: 1937,
title: 'The Hobbit'