closures - uninitialized vs undefined
Nobody has claimed this yet.
Assessment
- Difficulty
- 2/5
- Estimated time
- 1-3 hours
- Newbie friendliness
- 55/100
- Issue type
- Documentation
- Clarity
- Mostly clear
- Activity status
- Quiet
- Tech stack
- javascript
- Domain
- documentation
Research direction
Start with the closure article's lexical-environment and nested-function sections, then compare the labels in lexenv-nested-makecounter-2.svg and lexenv-nested-makecounter-3.svg. Verify whether the diagrams should distinguish from undefined, and update those SVGs only if the JavaScript behavior supports the proposed correction.
Written by the indexing model from the issue text.
Description
in this article, we are discussing lexical environments, and the scope of variables.
upon initialization, variables are defined as <unitialized> because "the engine knows about the variable, but it cannot be referenced until it has been declared with let"
later in the article, when referencing nested lexical environments in functions, a variable is initialized as undefined. from my understanding, this is incorrect, as the engine knows about the variable, but is not referenced yet since it hasn't been declared.
i believe that we need to change the following SVG's to reflect this change:
https://github.com/javascript-tutorial/en.javascript.info/blob/master/1-js/06-advanced-functions/03-closure/lexenv-nested-makecounter-2.svg
https://github.com/javascript-tutorial/en.javascript.info/blob/master/1-js/06-advanced-functions/03-closure/lexenv-nested-makecounter-3.svg
if this is an incorrect assumption, please help me understand why it's undefined instead of uninitialized! i'd love to learn more about how this all works.
- Dominant language
- HTML
- Stars
- 25.5k
- Forks
- 4k
- PR merge metrics
- No merged PRs in 30d
Contributor guide
No contributing guide indexed for this repository
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
More from javascript-tutorial/en.javascript.info
-
Difficulty 1/5 1-3 hours Newbie friendliness 88/100
-
Difficulty 2/5 1-3 hours Newbie friendliness 84/100
-
Difficulty 1/5 Under an hour Newbie friendliness 92/100
-
Keyboard events: keydown filtering example can't block IME-composed input (Korean/Japanese/Chinese) Open
Difficulty 2/5 1-3 hours Newbie friendliness 76/100
javascript-tutorial/en.javascript.info#3978 · 1 comment ·
-
Difficulty 2/5 1-3 hours Newbie friendliness 72/100
All issues in javascript-tutorial/en.javascript.info
Similar issues
-
triage
Difficulty 1/5 1-3 hours Newbie friendliness 88/100
-
enhancement
Difficulty 2/5 1-3 hours Newbie friendliness 72/100
-
feature pydanty:is-working
Difficulty 1/5 Under an hour Newbie friendliness 88/100
pydantic/pydantic-ai#8647 ·
-
Difficulty 2/5 1-3 hours Newbie friendliness 68/100
-
:watch: Not Triaged dotnet-fsharp/svc
Difficulty 1/5 Under an hour Newbie friendliness 90/100