FlipFlop (Super Edition)

The Big Idea

You will write a function that takes a number and returns "Flip", "Flop", "FlipFlop", or the number itself — based on divisibility rules. Then you will write a second function that applies the first to an entire array. This challenge requires you to pseudocode your approach before writing any code.

Your Roadmap

The challenge

Write a function called flipflop that takes a number and returns:

• "FlipFlop" if the number is divisible by both 3 and 5
• "Flop" if divisible by 5 only
• "Flip" if divisible by 3 only
• The number itself if none of the above apply

flipflop(3)   // "Flip"
flipflop(5)   // "Flop"
flipflop(15)  // "FlipFlop"
flipflop(7)   // 7

Then write a function called superFlipFlop that takes an array of numbers and returns a new array with the FlipFlop rules applied to each element:

superFlipFlop([1, 2, 3])      // [1, 2, "Flip"]
superFlipFlop([1, 2, 5])      // [1, 2, "Flop"]
superFlipFlop([1, 2, 15])     // [1, 2, "FlipFlop"]
superFlipFlop([30, 9, 20, 1]) // ["FlipFlop", "Flip", "Flop", 1]

Key tool: The remainder operator (%) tells you if a number divides evenly:

if (i % 3 === 0) // true if i is divisible by 3

Plan your code

Before writing any code, write pseudocode comments describing your steps.

Write your plan in plain English as comments in your file. For example:

// check if the number is divisible by both 3 and 5
// if yes, return "FlipFlop"
// ...

Your pseudocode does not need to be perfect. It is a first draft — you will change it as you go. The point is to think before you type.

Write and test

Run the tests:

npm test 3-super-flipflop

Write your initial solution to match your pseudocode. Run the tests. If they pass, move on. If not, read the error messages and adjust.