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Port global var description to let #30388

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merged 2 commits into from
Nov 20, 2023
Merged

Port global var description to let #30388

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Port global var description to let
Josh-Cena Nov 20, 2023
af3edc6
Update files/en-us/web/javascript/reference/statements/let/index.md
hamishwillee Nov 20, 2023
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7 changes: 6 additions & 1 deletion files/en-us/web/javascript/reference/statements/let/index.md
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Expand Up @@ -39,7 +39,10 @@ The scope of a variable declared with `let` is one of the following curly-brace-
- Function body
- [Static initialization block](/en-US/docs/Web/JavaScript/Reference/Classes/Static_initialization_blocks)

Or the current module or script, if it's contained in none of these.
Or if none of the above applies:

- The current [module](/en-US/docs/Web/JavaScript/Guide/Modules), for code running in module mode
- The global scope, for code running in script mode.

Compared with {{jsxref("Statements/var", "var")}}, `let` declarations have the following differences:

Expand Down Expand Up @@ -104,6 +107,8 @@ This differs from using `typeof` for undeclared variables, and variables that ho
console.log(typeof undeclaredVariable); // "undefined"
```

> **Note:** `let` and `const` declarations are only processed when the current script gets processed. If you have two `<script>` elements running in script mode within one HTML, the first script is not subject to the TDZ restrictions for top-level `let` or `const` variables declared in the second script, although if you declare a `let` or `const` variable in the first script, declaring it again in the second script will cause a [redeclaration error](#redeclarations).

### Redeclarations

`let` declarations cannot be in the same scope as any other declaration, including `let`, {{jsxref("Statements/const", "const")}}, {{jsxref("Statements/class", "class")}}, {{jsxref("Statements/function", "function")}}, {{jsxref("Statements/var", "var")}}, and {{jsxref("Statements/import", "import")}} declaration.
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