freeCodeCamp/curriculum/challenges/german/15-javascript-algorithms-an.../learn-form-validation-by-bu.../step-021.md

3.4 KiB

id title challengeType dashedName
5e302e80e003129199103c78 Step 21 0 step-21

--description--

To track how the reduce() function works, log the values of the accumulator and currentValue in the callback function before the return statement like this: console.log({ accumulator })

You can also check your progress by adding console.log({ total }) at the end of the calculate() function.

When you enter calorie values in the form and push the Calculate button, you will see the values of accumulator and currentValue in each iteration of the reduce() callback function.

--hints--

See description above for instructions.

assert(code.replace(/\s/g, '').match(/console.log\({accumulator}\)/));

--seed--

--before-user-code--

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <title></title>
    <meta name="description" content="" />
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <link rel="stylesheet" href="styles.css" />
  </head>
  <body>
    <div class="container">
      <form id="calorie-form">
        <h2 class="center">Calorie Counter</h2>
        <div class="grid">
          <legend>Sex</legend>
          <div>
            <input type="radio" name="sex" id="female" value="F" checked />
            <label for="female">
              Female (2,000 calories)
            </label>

            <div>
              <input type="radio" name="sex" id="male" value="M" />
              <label for="male">
                Male (2,500 calories)
              </label>
            </div>
          </div>
        </div>
        <div class="grid" id="entries">
          Breakfast
          <input
            type="number"
            min="0"
            class="cal-control"
            id="breakfast"
          /><br />
          Lunch
          <input type="number" min="0" class="cal-control" id="lunch" /><br />
          Dinner <input type="number" min="0" class="cal-control" id="dinner" />
        </div>
        <button type="button" class="btn-add" id="add">
          Add Entry
        </button>
        <button type="submit" class="btn-solid" id="calculate">
          Calculate
        </button>
        <button type="button" class="btn-outline" id="clear">
          Clear
        </button>
      </form>
      <div id="output"></div>
    </div>
  </body>
</html>

--after-user-code--

  </body>
</html>

--seed-contents--

<script>
  document.getElementById('calorie-form').onsubmit = calculate;

--fcc-editable-region--
  function calculate(e) {
    e.preventDefault();

    const total = Array.from(document.getElementsByClassName('cal-control'))
      .map(meal => Number(meal.value))
      .reduce((accumulator, currentValue) => {
        // log the values of the `accumulator` and `currentValue` here
        return accumulator + currentValue;
      }, 0);

    // log the value of `total` here
  }
--fcc-editable-region--
</script>

--solutions--

<script>
  document.getElementById('calorie-form').onsubmit = calculate;

  function calculate(e) {
    e.preventDefault();

    const total = Array.from(document.getElementsByClassName('cal-control'))
      .map(meal => Number(meal.value))
      .reduce((accumulator, currentValue) => {
        console.log({ accumulator });
        console.log({ currentValue });
        return accumulator + currentValue;
      }, 0);

    console.log({ total });
  }
</script>