javascript - 如何使用 `requires` 重置类原型(prototype)

Question

为了举例，这里有一些人为的东西:

var util = require('util');
var Me = require('./me.js');

console.log(util.inspect(Me.prototype.something.toString())); // #1      

Me.prototype.name = function() {
  console.log('different');
};

console.log(util.inspect(Me.prototype.something.toString())); // #2

// re-init prototype
var Me = require('./me.js');
console.log(util.inspect(Me.prototype.something.toString())); // #3

输出:

'function () {\n    console.log(\'original\');\n}'
'function () {\n    console.log(\'different\');\n}'
'function () {\n    console.log(\'different\');\n}'

为什么 require 调用不重新初始化 Me 类原型(prototype)？

Answer 1

来自 Nodejs 文档，LINK

Modules are cached after the first time they are loaded. This means (among other things) that every call to require('foo') will get exactly the same object returned, if it would resolve to the same file.

Multiple calls to require('foo') may not cause the module code to be executed multiple times. This is an important feature. With it, "partially done" objects can be returned, thus allowing transitive dependencies to be loaded even when they would cause cycles.

If you want to have a module execute code multiple times, then export a function, and call that function.