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Clarify precedence of comma operator in article and add missing "let"… #3974

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Clarify precedence of comma operator in article and add missing "let"… #3974

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4 changes: 2 additions & 2 deletions 1-js/02-first-steps/08-operators/article.md
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Original file line number Diff line number Diff line change
Expand Up @@ -459,7 +459,7 @@ alert( a ); // 7 (the result of 3 + 4)
Here, the first expression `1 + 2` is evaluated and its result is thrown away. Then, `3 + 4` is evaluated and returned as the result.

```smart header="Comma has a very low precedence"
Please note that the comma operator has very low precedence, lower than `=`, so parentheses are important in the example above.
Please note that the comma operator has the lowest precedence, lower than `=`, so parentheses are important in the example above.

Without them: `a = 1 + 2, 3 + 4` evaluates `+` first, summing the numbers into `a = 3, 7`, then the assignment operator `=` assigns `a = 3`, and the rest is ignored. It's like `(a = 1 + 2), 3 + 4`.
```
Expand All @@ -472,7 +472,7 @@ For example:

```js
// three operations in one line
for (*!*a = 1, b = 3, c = a * b*/!*; a < 10; a++) {
for (*!*let a = 1, b = 3, c = a * b*/!*; a < 10; a++) {

@chatgpt-codex-connector chatgpt-codex-connector Bot Jul 25, 2026

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P2 Badge Keep the loop initializer as a comma expression

Adding let changes this initializer from a comma expression into a lexical declaration containing three declarators, where the commas are separators rather than instances of the comma operator. Consequently, the section's final example no longer demonstrates the operator it claims frameworks use; declare the variables separately and retain the assignment expression in the initializer, or otherwise use an actual comma expression here.

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...
}
```
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