确保“这个”的最佳做法是什么？ Javascript中的上下文？ [英] What is a best practice for ensuring "this" context in Javascript?

问题描述

以下是一个简单的Javascript类示例，其中包含公共和私有方法（小提琴： http://jsfiddle.net / gY4mh / ）。

Here's a sample of a simple Javascript class with a public and private method (fiddle: http://jsfiddle.net/gY4mh/).

function Example() {
    function privateFunction() {
       // "this" is window when called.
       console.log(this);
    }

    this.publicFunction = function() {
       privateFunction();
    }
}

ex = new Example;
ex.publicFunction();

从公共场所调用私有函数会导致this成为窗口对象。我应该如何确保使用类上下文而不是窗口调用我的私有方法？这是不可取的吗？

Calling the private function from the public one results in "this" being the window object. How should I ensure my private methods are called with the class context and not window? Would this be undesirable?

推荐答案

使用闭包。基本上在函数中声明的任何变量仍然可用于该函数内的函数：

Using closure. Basically any variable declared in function, remains available to functions inside that function :

var Example = (function() {
    function Example() {
        var self = this; // variable in function Example
        function privateFunction() {                  
            // The variable self is available to this function even after Example returns. 
            console.log(self);
        }

        self.publicFunction = function() {
            privateFunction();
        }
    }

    return Example;
})();

ex = new Example;
ex.publicFunction();

这篇关于确保“这个”的最佳做法是什么？ Javascript中的上下文？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！