Guided Notes
Functions
Declarations, expressions, and arrow functions; parameters, defaults, and return; scope, hoisting, and closures.
Why functions?
Slide 1 / 5A function is a reusable block of code with a name. Define it once, call it anywhere:
function toCelsius(fahrenheit) { return (fahrenheit - 32) * 5 / 9; } toCelsius(212) → 100
Functions make code shorter, easier to test, and easier to change — fix the formula in one place and every caller benefits.