Function execution context in Javascript - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a function execution context in JavaScript?

It is the environment where a function runs. It stores information like variables, parameters, and the value of this while the function executes.

intermediate

What are the three main parts of a function execution context?

1. Variable Environment (stores variables and parameters)<br>2. Scope Chain (links to outer contexts)<br>3. this value (context of the function call)

beginner

When is a function execution context created?

It is created every time a function is called, before the function code runs, and destroyed after the function finishes.

intermediate

How does the scope chain affect variable access inside a function?

The scope chain lets the function access variables from its own context and from outer contexts, like the global scope or parent functions.

advanced

What is the value of this inside a function execution context?

It depends on how the function is called. For example, in a regular function call, this is undefined in strict mode or the global object otherwise. In methods, this is the object owning the method.

When is a new function execution context created in JavaScript?

A Every time a function is called

B Only once when the function is defined

C When the script loads

D When the browser refreshes

A new execution context is created each time a function is called to keep track of its variables and state.

Which part of the function execution context stores the function's parameters and local variables?

A Variable Environment

B Scope Chain

C <code>this</code> value

D Call Stack

The Variable Environment holds the function's parameters and local variables.

What does the scope chain in a function execution context do?

A Defines the value of <code>this</code>

B Stores the function's code

C Links to outer variable environments for variable lookup

D Manages asynchronous calls

The scope chain connects the current context to outer contexts to find variables.

What is the value of this inside a regular function call in strict mode?

A The global object

B The object owning the function

C The function itself

D Undefined

In strict mode, this is undefined in regular function calls.

What happens to a function execution context after the function finishes running?

A It stays in memory forever

B It is destroyed and removed from the call stack

C It becomes global context

D It pauses until called again

After the function finishes, its execution context is removed from the call stack and destroyed.

Explain what a function execution context is and what it contains.

Think about what the function needs to remember while it runs.

Describe how the scope chain works inside a function execution context.

Imagine looking for a variable inside nested boxes.