摘要：堆棧結構的底部是全局執行上下文，頂部是當前執行上下文。不同的執行上下文切換時堆棧會發生改變譯論及代碼類型時，在某些時候可能也意味著執行上下文。函數體中代碼執行完后，只剩全局上下文直到程序結束譯代碼更有意思。

第一次翻譯，希望各位多多包涵，有錯誤處還望指出，歡迎提出建議。

Introduction （介紹）

Definitions （定義）

Types of excutable code （可執行代碼的類型）

Global code（全局代碼）

Funcion code（函數代碼）

Eval code（eval代碼）

Conclusion（結論）

Additional literature （文獻參考）

In this note we will metion execution contexts of ECMAScript and types of executable code related with them.

譯：在這篇筆記中，我們將討論執行環境和相關的可執行代碼類型。

Every time when control is transferred to ECMAScript executable code, control is entered an execution context.

譯：當控制流即將執行代碼時，總是先進入執行上下文

Execution context( abbreviated from - EC) is the abstract concept used by ECMA-262 specification for typification and differentation of an executable code.

譯：執行上下文（縮寫為EC）是ECMA-262使用的抽象概念，通常用來表示可執行代碼的類型和區別。

The standard does not define accurate structure and kind of EC from the technical implementation viewpoint; it is a question of the ECMAScript-engines implementing the standard.

譯：官方標準沒有定義EC的確切結構和技術實現，按照規范來實現依然ECMAScript引擎的問題

Logically, set of active execution contexts forms a stack. The bottom of this stack is always a global context, the top - a current (active) execution context. The stack is modified (pushed/popped) during the entering and exiting various kinds of EC.

譯：從邏輯上來看，許多激活的執行上下文會形成一個堆棧結構。堆棧結構的底部是全局執行上下文，頂部是當前執行上下文。不同的執行上下文切換時堆棧會發生改變

With abstract concept of an execution context, the concept of type of an executable code is related. Speaking about code type, it is possible in the certain moments to mean an execution context.

譯：論及代碼類型時，在某些時候可能也意味著執行上下文。可執行上下文的抽象概念和其類型是分不開的

For examples, we define the stack of execution contexts as an array:

譯：例如，我們將執行上下文的堆棧定義為數組

ECStack = [];

The stack is pushed every time on entering a function (even if the function is called recursively or as the constructor), and also at built-in eval function work.

譯：控制流每次進入函數（即使該函數是遞歸調用或作為構造器）時，入棧就會發生，同樣內嵌在該函數中的eval函數也會引發入棧行為。

This type of code is processed at level Program: i.e. the loaded external .js -file or the local inline-code (inside the tags). The global code does not include any parts of a code which are in bodies of functions.

譯：這種類型的代碼是以程序級別處理的：比如說額外的js文件或者局部的內連代碼（在