使用map（）的意外逗号 [英] Unexpected comma using map()

问题描述

我有一个包含元素列表的数组：

I've an array with a list of elements:

  description: [
    'HTML & CSS',
    'Responsive Design Fundamentals',
    'Javascript object-oriented programming',
    'jQuery',
    'Website Performance Optimization',
    'CRP and RAIL',
    'REST API and Ajax',
    'Javascript Design patterns',
    'Bootsrap Framework',
    'Polymer Web Elements'
  ],

我正在尝试使用模板字符串将此列表附加到HTML元素：

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>

结果我得到一个意想不到的逗号每个列表元素之间（请参阅下面的代码段）

As a result I get an unexpected comma between each list element (see the snippet below)

如何避免这种情况？

编辑：已添加代码段

推荐答案

解释

模板文字使用 toString （）默认情况下，通过 map 将返回的数组与，连接起来的方法。< br>
为了避免这个问题你可以使用 join（''）

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('')

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>

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