Challenge 3 — Solution

Task: Declare one variable of each core type (number, string,
boolean, null, undefined) and use typeof to log each variable's type
alongside its value.

const aNumber = 42;
const aString = "Hello";
const aBoolean = true;
const aNull = null;
let aUndefined;

console.log(aNumber, typeof aNumber);
console.log(aString, typeof aString);
console.log(aBoolean, typeof aBoolean);
console.log(aNull, typeof aNull);
console.log(aUndefined, typeof aUndefined);


Expected output:

42 'number'
Hello 'string'
true 'boolean'
null 'object'
undefined 'undefined'


Notes:
- aUndefined is declared with let and given no value at all — this
  is exactly what produces the undefined type, distinct from aNull,
  which was deliberately set to null on purpose.
- typeof null famously returns "object", not "null" — a long-standing
  quirk in JavaScript dating back to its earliest versions, worth
  knowing about even though it looks like a mistake.
- Each variable here uses const except aUndefined, since giving a
  const no value at declaration time isn't allowed — const requires
  an initial value immediately.