什么是“访问者功能”？ [英] What is "accessor function"?

问题描述

在第4.3.26节中标准ECMA-262版本：

In section 4.3.26 of the Standard ECMA-262 Edition:

根据属性的形式，值可以直接表示为
作为数据值（原始值，对象或
函数对象）或间接由一对存取函数。

Depending upon the form of the property the value may be represented either directly as a data value (a primitive value, an object, or a function object) or indirectly by a pair of accessor functions.

I不明白访问器功能是什么意思，我没有在规范中找到访问器功能的定义。然后我搜索了网络。在我看来，访问器功能意味着getter。但是我仍然不明白，为什么属性值是由一对存取函数表示的？任何人都可以通过示例来说明这一点吗？谢谢！

I didn't understand what "accessor function" means and I didn't find the definition of accessor function in the specification. Then I searched the web. It seemed to me that accessor function means "getter". But I still don't understand, why is the property the value be represented "by a pair of accessor functions"? Can anyone illustrate this with example(s)? Thanks!

推荐答案

一对存取函数是getter和setter。

"A pair of accessor functions" are the getter and the setter.

文档和示例：

var o = {}; // Creates a new object

// Example of an object property added with defineProperty with an accessor property descriptor
var bValue = 38;
Object.defineProperty(o, 'b', {
  get: function() { return bValue; },
  set: function(newValue) { bValue = newValue; },
  enumerable: true,
  configurable: true
});

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