Javascript 自执行函数和变量作用域 [英] Javascript self executing functions and variable scope

问题描述

有人可以向我解释这种行为吗?

Could someone explain to me this behavior?

var obj = function()
{
    var _bar = 10;
    function i_bar(){return ++_bar;}

    return {
        bar  : _bar,
        i_bar: i_bar
    }
}();

obj.bar     // prints 10, OK
obj.i_bar() // prints 11, OK
obj.bar = 0 // prints 0,  OK
obj.i_bar() // prints 12, NOK

因为唯一的变量是_bar，不应该最后一个obj.i_bar()打印的是1而不是12?

Since the only variable is _bar, shouldn't the last obj.i_bar() have printed 1 instead of 12?

推荐答案

您的 bar 与 i_bar 所引用的引用不同.值类型不是通过引用，因此您将 bar 复制到返回对象中，但它不是您的函数所指的 bar.试试这个:

Your bar is not the same references as what i_bar is referencing. Value types are not by reference, so you are copying bar into the return object, but it is not the bar that your function is referring to. Try this:

var obj = function()
{
    var self = this;

    function i_bar(){return ++self.bar;}

    self.bar = 10;
    self.i_bar = i_bar;

    return self;
}();

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