Arrow Functions

1. Implicit returns work when the function body is a single expression—no braces, no return keyword needed
2. Arrow functions are perfect for callbacks because they're concise and don't rebind this (we'll learn about this later)
3. Function declarations are still best for top-level named functions because of hoisting and clearer stack traces

// Use arrow functions for callbacks
function applyToNumber(
	value: number,
	transform: (n: number) => number,
): number {
	return transform(value)
}

const result = applyToNumber(5, (n) => n + 1)

// Use function declarations for top-level functions
function processOrder(order: Order): Receipt {
	// ...
}