JavaScript作用域是什么的相关内容

文章 2021-11-13 来自：开发者社区

「注解」《你不知道的JavaScript（上卷）》第一章：作用域是什么

书名：《你不知道的JavaScript（上卷）》作者：Kyle Simpson译者：赵望野 , 梁杰1.1 编译原理在传统的编译语言的流程中，程序中的一段源代码在执行之前会经历以下三个步骤：词法分析语法分析代码生成1.2 理解作用域理解引擎、编译器、作用域编译器如何处理 var a = 2;总结：引擎在执行赋值操作之前会询问作用域中是否含有a这个变量，有则赋值，无则抛出异常，对编译器来说，遇到v....

文章 2021-11-13 来自：开发者社区

「注解」《你不知道的JavaScript（上卷）》第一章：作用域是什么

1.1 编译原理在传统的编译语言的流程中，程序中的一段源代码在执行之前会经历以下三个步骤：词法分析2. 语法分析3. 代码生成1.2 理解作用域理解引擎、编译器、作用域编译器如何处理 var a = 2;总结：引擎在执行赋值操作之前会询问作用域中是否含有a这个变量，有则赋值，无则抛出异常，对编译器来说，遇到var a则会先询问作用域中是否有a，是则继续，无则让作用域在当前作用域的集合中声明一个新....

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