--- id: 645cb0ce6dc93738b442b0d0 title: Step 65 challengeType: 0 dashedName: step-65 --- # --description-- Now you should see a countdown from `3` to `0`, followed by `Reached base case`, and a count from `1` to `3`. This is because, after the recursive loop is finished, the function will continue to execute the code after the recursive call. This is why you see `Reached base case` before the count from `1` to `3`. Now that you have a better understanding of how the call stack and recursion work, you'll refactor the `decimalToBinary()` function to use recursion instead of a `while` loop. First, remove your `countDownAndUp()` function and function call. # --hints-- Your code should not have a function named `countDownAndUp`. ```js assert.notMatch(code, /(var|let|const)\s+countDownAndUp\s*=\s*[\s\S]+\}/); ``` Your code should not call the `countDownAndUp` function. ```js assert.notMatch(code, /countDownAndUp\([\s\S]+\)/); ``` # --seed-- ## --seed-contents-- ```html Decimal to Binary Converter

Decimal to Binary Converter

``` ```css *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; } :root { --light-grey: #f5f6f7; --dark-blue: #1b1b32; --orange: #f1be32; } body { background-color: var(--dark-blue); font-family: "Times New Roman", Times, serif; font-size: 18px; color: var(--light-grey); padding: 0 15px; display: flex; flex-direction: column; align-items: center; } h1 { text-align: center; font-size: 2.3rem; margin: 20px 0; } .input-container { margin: 10px 0; display: flex; flex-direction: column; gap: 10px; justify-content: center; align-items: center; } .convert-btn { background-color: var(--orange); cursor: pointer; border: none; padding: 4px; } .number-input { height: 25px; } #result { margin: 10px 0; min-width: 200px; width: fit-content; min-height: 80px; word-break: break-word; padding: 15px; border: 5px solid var(--orange); font-size: 2rem; text-align: center; } #animation-container { margin: auto; max-width: 300px; } .animation-frame { margin: 250px auto 0; padding: 15px 10px; border: 5px solid var(--orange); font-size: 1.2rem; text-align: center; } @media screen and (min-width: 500px) { .input-container { flex-direction: row; } #result { max-width: 460px; } } ``` ```js const numberInput = document.getElementById("number-input"); const convertBtn = document.getElementById("convert-btn"); const result = document.getElementById("result"); --fcc-editable-region-- const countDownAndUp = (number) => { console.log(number); if (number === 0) { console.log("Reached base case"); return; } else { countDownAndUp(number - 1); console.log(number); } }; countDownAndUp(3); --fcc-editable-region-- const decimalToBinary = (input) => { let binary = ""; if (input === 0) { binary = "0"; } while (input > 0) { binary = (input % 2) + binary; input = Math.floor(input / 2); } result.innerText = binary; }; const checkUserInput = () => { if ( !numberInput.value || isNaN(parseInt(numberInput.value)) || parseInt(numberInput.value) < 0 ) { alert("Please provide a decimal number greater than or equal to 0"); return; } decimalToBinary(parseInt(numberInput.value)); numberInput.value = ""; }; convertBtn.addEventListener("click", checkUserInput); numberInput.addEventListener("keydown", (e) => { if (e.key === "Enter") { checkUserInput(); } }); ```