声明调用辅助函数的 javascript 原型函数的正确方法是什么 [英] What is the proper way to declare javascript prototype functions calling helper functions

问题描述

我正在尝试确定声明 javascript类"使用的辅助函数的最佳实践是什么.例如:

I'm trying to determine what is the best practice for declaring helper functions used by a javascript "class". For example:

方法一:

// closure issues?
function helper(param) {
  return compute(param);   
}

function HeavilyInstantiated() {}

HeavilyInstantiated.prototype.computeHard = function(params) {
   var someResult = helper(params.prop1);
   return someResult;
}

方法#2:

function HeavilyInstantiated() {}

// still, only one instance for all objects instantiated?
HeavilyInstantiated.prototype.helper = function(param) {
   return compute(param);  
}
HeavilyInstantiated.prototype.computeHard = function(params) {
   var someResult = this.helper(params.prop1);
   return someResult;
}

推荐答案

我更喜欢方法 3，将其声明为构造函数的一个属性:

I prefer method 3, declaring it as a property of the constructor:

function HeavilyInstantiated() {}

HeavilyInstantiated.helper = function(param) {
   return compute(param);  
}
HeavilyInstantiated.prototype.computeHard = function(params) {
   var someResult = HeavilyInstantiated.helper(params.prop1);
   return someResult;
}

你仍然只有一个辅助方法的实例，但它不会污染全局命名空间或 HeavilyInstantiated 的实例(它不在它们的原型链上).

You still have only one instance of the helper method, but it doesn't pollute the global namespace or the instances of HeavilyInstantiated (it is not on their prototype chain).

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