freeCodeCamp/part-021.md at 895e6b8daf6338920221fa33ff4be59eef815e89

chore(learn): Remove remaining isHidden keys from frontmatter (English and Chinese challenges) (#39809 )

* fix: remove isHidden key from tool template

* fix: removed isHidden key from English challenges

* fix: remove isHidden key from Chinese challenges

2020-10-08 14:18:47 +02:00

3.6 KiB

Raw Blame History

id, title, challengeType

id	title	challengeType
5e302e80e003129199103c78	Part 21	0

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.

Instructions

Tests

tests:
  - text: See description above for instructions.
    testString: assert( code.replace(/\s/g, '').match(/console.log\({accumulator}\)/) );

Challenge Seed

<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) => {
        // log the values of the `accumulator` and `currentValue` here
        return accumulator + currentValue;
      }, 0);

    // log the value of `total` here
  }
</script>

Before Test

<!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 Test

  </body>
</html>

Solution

<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>

3.6 KiB Raw Blame History