javascript - Unexpected comma using map()

Question

I've an array with a list of elements and I'm trying to append this list to an HTML element using template strings:

var description = [
  'HTML & CSS',
  'Javascript object-oriented programming',
  'Progressive Web apps (PWAs)',
  'Website Performance Optimization',
  'Webpack and Gulp workflows',
  'Fullstack React.js',
  'Web Components',
  'Responsive web design',
  'Sketch design',
  'GraphQL and Relay'
]

$('body').append(
  `
  <div class="description">
    <ul>
      ${description.map(
        function(work) {
          return `<li>${work}</li>`
        }
      )}</ul>
  </div>
  `
)

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

Answer 1

Explanation

template literals use the toString() method which by default joins the returned array by map with a ,.
To avoid this "problem" you can use join('')

Code

var description = [
  'HTML & CSS',
  'Javascript object-oriented programming',
  'Progressive Web apps (PWAs)',
  'Website Performance Optimization',
  'Webpack and Gulp workflows',
  'Fullstack React.js',
  'Web Components',
  'Responsive web design',
  'Sketch design',
  'GraphQL and Relay'
]

$('body').append(
  `
  <div class="description">
    <ul>
     ${
        description.map(function(work) {
          return `<li>${work}</li>`
        }).join('')
      }
    </ul>
  </div>
  `
)

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>