Challenge 1 — Solution

Task: Write a function makePowerOf(exponent) that returns a function
taking a base number and returning base raised to that exponent
(use ** for exponentiation). Create square = makePowerOf(2) and
cube = makePowerOf(3), then test both with the same input.

function makePowerOf(exponent) {
    return function (base) {
        return base ** exponent;
    };
}

const square = makePowerOf(2);
const cube = makePowerOf(3);

console.log(square(5));   // 25
console.log(cube(5));     // 125


Expected output:

25
125


Notes:
- square and cube are two separate closures, each created by its own
  call to makePowerOf — square's inner function remembers exponent
  as 2, cube's remembers it as 3, with no overlap between them.
- ** is JavaScript's exponentiation operator (5 ** 2 means 5 squared),
  separate from the * multiplication operator used in earlier
  chapters.
- Both functions can be called repeatedly with different bases
  (square(10), square(3), etc.) and exponent stays fixed at whatever
  value was passed to makePowerOf when that specific function was
  created.