JavaScript作用域深度剖析的相关内容

文章 2023-08-31 来自：开发者社区

JavaScript作用域深度剖析：动态作用域

前言• 在上篇文章中, 我们说了作用域一共分为两种：词法作用域和动态作用域，而这篇文章我们一起来学习动态作用域。动态作用域• 动态作用域似乎有着很好的理由让作用域作为一个在运行时就被动态确定的形式，而不是在写代码时进行静态确定的形式。• 考虑一下代码：function foo() { console.log(a); // 2 } function bar() { var a =...

文章 2023-08-31 来自：开发者社区

JavaScript作用域深度剖析：从局部到全局一网打尽1.1 编译原理• JavaScript 事实上是一门编译语言。• 在传统编译语言中，一段源代码执行前会经历三个步骤:1. 分词/词法分析(Tokenizing/Lexing)var a =2;// 分解后：var、a、=、2、;// 空格是否会被当做词法单元，取决于空格在这门语言中是否具有意义。• 期间经过两个过程：分词(tokenizi....

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更新时间 2023-09-21 09:58:11

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