导出模块节点。js[重复]

仅在某个地方需要模块a(例如,在模块B中)并不能使a的功能在其他模块中可以访问。通常情况下,在模块B中甚至无法访问它们。

要从另一个模块访问函数(或任何值),该另一个模块必须 他们以下场景将不起作用:

// module-a.js
function firstFunction () {}
function secondFunction () {}

// module-b.js
var helper_handleSentences = require('/handleSentences.js'); 
// do something with 'helper_handleSentences'
module.exports = function (a) {
  return helper_handleSentences(a);
}

module-a.js 不导出任何内容。因此,变量 a 保存默认导出值,该值为空对象。

1 mainModule.js

// handleSentences.js
function doSomethingSecret () {
  // this function can only be accessed in 'handleSentences.js'
}
function handleSentences () {
  // this function can be accessed in any module that requires this module
  doSomethingSecret();
}
module.exports = handleSentences;

// formatModule.js
var helper_handleSentences = require('/handleSentences.js'); 
// do something with 'helper_handleSentences'
module.exports = function (a) {
  return helper_handleSentences(a);
};

// mainModule.js
var helper_handleSentences = require('/handleSentences.js');
var helper_formatModule = require('/formatModule.js'); 
// do something with 'helper_handleSentences' and 'helper_formatModule'

2、将两个模块的导出值合并到一个对象中

//handleSentences.js
//此函数只能在“handlementes.js”中访问
//可以在需要此模块的任何模块中访问此功能
doSomethingSecret();
}

// formatModule.js
var helper_handleSentences = require('/handleSentences.js'); 
// do something with 'helper_handleSentences'
function formatModule (a) {
  return helper_handleSentences(a);
};
module.exports = {
  handleSentences: helper_handleSentences,
  format: formatModule
};

// mainModule.js
var helper_formatModule = require('/formatModule.js');
// use both functions as methods
helper_formatModule.handleSentences();
helper_formatModule.format('...');