require（'mypackage.js'）和require（'mypackage'）有什么区别？

Both these require statements appear to work the same way:

这两个需要语句似乎都以相同的方式工作：

var Mypackage = require('mypackage.js');

var Mypackage = require（'mypackage.js'）;

var Mypackage require('mypackage');

var Mypackage require（'mypackage'）;

Is there a difference between them?

它们之间有区别吗？

1 个解决方案

#1

Here is the answer:

这是答案：

Module.prototype.load = function(filename) {
  debug('load ' + JSON.stringify(filename) +
        ' for module ' + JSON.stringify(this.id));

  assert(!this.loaded);
  this.filename = filename;
  this.paths = Module._nodeModulePaths(path.dirname(filename));

  var extension = path.extname(filename) || '.js';
  if (!Module._extensions[extension]) extension = '.js';
  Module._extensions[extension](this, filename);
  this.loaded = true;
};

1. Node.JS looks to see if the given module is a core module. (e.g. http, fs, etc.) Always takes the precedence in the loading modules.
2. Node.JS查看给定模块是否是核心模块。 （例如http，fs等）始终在加载模块中优先。
3. If the given module is not a core module (e.g. http, fs, etc.), Node.js will then begin to search for a directory named, node_modules.
   It will start in the current directory (relative to the currently-executing file in Node.JS) and then work its way up the folder hierarchy, checking each level for a node_modules folder. Once Node.JS finds the node_modules folder, it will then attempt to load the given module either as a (.js) JavaScript file or as a named sub-directory; if it finds the named sub-directory, it will then attempt to load the file in various ways. So, for example
4. 如果给定模块不是核心模块（例如http，fs等），则Node.js将开始搜索名为node_modules的目录。它将从当前目录（相对于Node.JS中当前正在执行的文件）开始，然后沿文件夹层次结构向上工作，检查node_modules文件夹的每个级别。一旦Node.JS找到node_modules文件夹，它就会尝试将给定模块加载为（.js）JavaScript文件或命名子目录;如果它找到了命名的子目录，它将尝试以各种方式加载文件。所以，例如
5. If you make a request to load the module, "utils" and its a directory not a .js file then:
   Node.JS will search a hierarchical directory for node_modules and utils in the following ways:
   ./node_modules/utils.js
./node_modules/utils/index.js
./node_modules/utils/package.json
6. 如果您请求加载模块，“utils”及其目录而不是.js文件，那么：Node.JS将通过以下方式在分层目录中搜索node_modules和utils：./ node_modules / utils.js ./ node_modules / utils / index.js ./node_modules/utils/package.json
7. If Node.JS still can't find the file in above steps, Node.js will then start to look into the directory paths from environment variables i.e. NODE_PATH set on your machine(obviously set by Node.JS installer file if you are on windows) Not Found in all the above steps then, prints a stack trace to stder
   E.g.: Error:Cannot find module 'yourfile'
   For more information: link is here even the cyclic require() is explained very well.
8. 如果Node.JS仍然无法在上面的步骤中找到该文件，Node.js将开始从您的机器上设置的环境变量（即NODE_PATH）开始查看目录路径（如果您在Windows上，显然由Node.JS安装程序文件设置） ）在上述所有步骤中都找不到，然后将堆栈跟踪打印到stder Eg：错误：找不到模块'yourfile'有关更多信息：链接在这里，甚至循环require（）也很好地解释了。