Learn Recursion by Building a Decimal to Binary Converter - Step 12

JavaScript
1

Tell us what’s happening:

I wrapped it in the isNaN function and the rest I am so confused on.

Your code so far

if (!numberInput.value || isNaN(parseInt(numberInput.value || return < 0))) {

}
not sure what I am doing wrong. Somebody please help me.

<!-- file: index.html -->
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Decimal to Binary Converter</title>
    <link rel="stylesheet" href="styles.css" />
  </head>
  <body>
    <h1>Decimal to Binary Converter</h1>
    <div class="input-container">
      <label for="number-input">Enter a decimal number:</label>
      <input
        value=""
        type="number"
        name="decimal number input"
        id="number-input"
        class="number-input"
      />
      <button class="convert-btn" id="convert-btn">Convert</button>
    </div>
    <output id="result" for="number-input"></output>
    <div id="animation-container"></div>
    <script src="script.js"></script>
  </body>
</html>

/* file: styles.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;
  }
}

/* file: script.js */
const numberInput = document.getElementById("number-input");
const convertBtn = document.getElementById("convert-btn");
const result = document.getElementById("result");

const checkUserInput = () => {

// User Editable Region

  if (!numberInput.value || isNaN(parseInt(numberInput.value || return < 0))) {
  
  }

// User Editable Region


  console.log(numberInput.value);
};

convertBtn.addEventListener("click", checkUserInput);

numberInput.addEventListener("keydown", (e) => {
  if (e.key === "Enter") {
    checkUserInput();
  }
});

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36

Challenge Information:

Learn Recursion by Building a Decimal to Binary Converter - Step 12

2

they wanted you to check if parseInt(numberInput.value) isNaN but you’re trying to check if the result of parseInt ORed with return < 0 -altogether- isNaN.
You need to move the OR part outside the isNaN

3

Hello @redneckcornerts

The exercise asks you to do two things:

  • Wrap the parseInt call with a isNaN.
  • Add a third condition to check if the number is < 0 (negative number).

As I can see in your code the first step looks good but there is something wrong in your third condition:
return < 0 does not look right.
Think again about check if the number parseInt(numberInput.value) is less than 0.

Also be careful with the parenthesis, remember to close the isNaN parenthesis before adding the third || condition

1 Like