javascript - 无法从 JS 中的简单模块调用方法

Question

我试图通过使用 getPosts 函数在调用时返回它来从我的模块（Tweeter）中传递一个数组（_posts）。

当我尝试打印/传递它时 - 它只是打印函数的代码而不是返回数组。

const Tweeter = function() {
  const _posts = [{
      text: "First post!",
      id: "p1",
      comments: [{
          id: "c1",
          text: "First comment on first post!"
        },
        {
          id: "c2",
          text: "Second comment on first post!!"
        },
        {
          id: "c3",
          text: "Third comment on first post!!!"
        }
      ]
    },
    {
      text: "Aw man, I wanted to be first",
      id: "p2",
      comments: [{
          id: "c4",
          text: "Don't wory second poster, you'll be first one day."
        },
        {
          id: "c5",
          text: "Yeah, believe in yourself!"
        },
        {
          id: "c6",
          text: "Haha second place what a joke."
        }
      ]
    }
  ]

  const getPosts = function() {
    return _posts
  }

  return {
    getPosts: getPosts
  }

}

标签： javascriptmodulescope

Answer 1

定义完成后，需要新建一个 Tweeter 对象，比如

const tweets = new Tweeter();
// now you can do
tweets.getPosts();

或者您可以简单地调用您的函数定义，例如：

const Tweeter = function() {
  const _posts = [{
      text: "First post!",
      id: "p1",
      comments: [{
          id: "c1",
          text: "First comment on first post!"
        },
        {
          id: "c2",
          text: "Second comment on first post!!"
        },
        {
          id: "c3",
          text: "Third comment on first post!!!"
        }
      ]
    },
    {
      text: "Aw man, I wanted to be first",
      id: "p2",
      comments: [{
          id: "c4",
          text: "Don't wory second poster, you'll be first one day."
        },
        {
          id: "c5",
          text: "Yeah, believe in yourself!"
        },
        {
          id: "c6",
          text: "Haha second place what a joke."
        }
      ]
    }
  ]

  const getPosts = function() {
    return _posts
  }

  return {
    getPosts: getPosts
  }

}();

现在你可以简单地做，Tweeter.getPosts();

如果您要从文件中导出它，您可以简单地执行以下操作：

export const Tweeter = function() {
  const _posts = [{
      text: "First post!",
      id: "p1",
      comments: [{
          id: "c1",
          text: "First comment on first post!"
        },
        {
          id: "c2",
          text: "Second comment on first post!!"
        },
        {
          id: "c3",
          text: "Third comment on first post!!!"
        }
      ]
    },
    {
      text: "Aw man, I wanted to be first",
      id: "p2",
      comments: [{
          id: "c4",
          text: "Don't wory second poster, you'll be first one day."
        },
        {
          id: "c5",
          text: "Yeah, believe in yourself!"
        },
        {
          id: "c6",
          text: "Haha second place what a joke."
        }
      ]
    }
  ]

  const getPosts = function() {
    return _posts
  }

  return {
    getPosts: getPosts
  }

};

现在您可以导入其他文件，例如：

import {Tweeter} from './tweeter.js';

// use it like
const tweets = new Tweeter();
const posts = tweets.getPosts();

希望能帮助到你。