js底层运行机制代码演示 VO/GO

落日映苍穹つ 2023-02-21 14:02 13阅读 0赞

#### js底层运行机制 代码演示 VO/GO ####

VO 变量对象  
GO 全局对象  
ECStack 执行环境栈  
EC 全局执行上下文

var a = 12;
        var b = a;
        b = 13;
        console.log(a);

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1ajE5MzU_size_16_color_FFFFFF_t_70_pic_center]

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var a = {  n: 12 };
         var b = a;
         b['n'] = 13;
         console.log(a.n);

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1ajE5MzU_size_16_color_FFFFFF_t_70_pic_center 1]

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var a = {  n: 12 };
         var b = a;
         b = {  n: 13 };
         console.log(a.n);

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1ajE5MzU_size_16_color_FFFFFF_t_70_pic_center 2]

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/* 1.创建值 - 开辟一个堆 AAAFFF000 - 储存键值对 name : '你好' fn : 自执行函数执行，需要把obj.name 的值当做实参传递过来，这个时候obj还没关联 ==》 undefined.name // Cannot read property 'name' of undefined ==》 undefined不能读name属性 */
        var obj = { 
            name: '你好',
            fn: (function(x) { 
                return x + 10;
            })(obj.name)
        };
        console.log(obj.fn);

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1ajE5MzU_size_16_color_FFFFFF_t_70_pic_center 3]

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![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d1ajE5MzU_size_16_color_FFFFFF_t_70_pic_center 4]

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