"Having a look at the rule typescript:S7728 and after reading the article: ‘for…of vs forEach Which one is better?’ | by Aditya Yadav | Medium , I tested the proposed benchmark: const largeArray = Array.from({ length: 1e6 }, (_, i) => i); // for...of console.time('for...of'); for (const item of larg…

Hello @Fred_D , this is a very valid point. We are aware that .forEach may outperform for..of, but the same could be said about a classic for loop, which is usually the most performant. In scenarios where performance is a key aspect, I agree this rule can be disabled. But for most cases, the advant…

So maybe the explanation of the issue: “The forEach method creates a function call for each array element, which introduces performance overhead compared to native for...of loops. This overhead becomes more significant with larger arrays,” should be mitigated.

The answer is indeed that it’s complicated. Simple benchmarks may go either way. I experimented some more with Node 20. A for…of loop is defined in ECMAScript in a complicated way involving returning a new object with value and done fields for every item. This probably explains why it runs slower w…

Use `for…of` instead of `.forEach(…)` typescript:S7728

Rules and Languages

victor.diez (Victor Diez) November 7, 2025, 10:36am 5

You’re right. I removed any mention of performance degradation in the rule description: Remove performance as a downside of forEach by vdiez · Pull Request #5851 · SonarSource/rspec · GitHub

Topic		Replies	Views
Use `for…of` instead of `.forEach(…)` typescript:S7728, javascript:S7728 Rules and Languages javascript , typescript	2	411	November 13, 2025
S7728 FP Use "for...of" loops instead of "forEach" method calls Report False-positive / False-negative... javascript , sonarqube-cloud	5	1052	October 16, 2025
S7728 FP Use “for…of” loops instead of “forEach” method calls when object is not an iterable type Report False-positive / False-negative... javascript , typescript	1	89	October 30, 2025
typescript:S4138 should not apply to non-arrays Report False-positive / False-negative... typescript	2	924	April 4, 2022
FP seeking for-of where Typescript prohibits it Report False-positive / False-negative... typescript	6	874	September 15, 2022

Use `for…of` instead of `.forEach(…)` typescript:S7728

Related topics