Benchmark: Iteration through array; of vs forEach

Script Preparation code:

arr = [1,2,3,4,5]

Tests:

of
for (val of arr) Number(val)
forEach
arr.forEach(val => Number(val))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
of
forEach

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.3 Safari/605.1.15

Browser/OS: Safari 26 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
of	43173324.0 Ops/sec
forEach	133998216.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmarking test cases.

**What is being tested?**

The test case measures the performance difference between two approaches to iterate over an array and perform an operation on each element: `forEach` vs direct iteration using `for...of`.

**Options compared:**

1. **`forEach"`**: This is a built-in JavaScript method that allows iterating over an iterable object (like an array) while executing a block of code for each element.
2. **Direct iteration using `for...of```**: This approach uses the `for...of` loop syntax to iterate over an array, which is a more traditional and explicit way of looping.

**Pros and Cons:**

*   **`forEach"`:**
    *   Pros:
        *   More concise and readable code.
        *   Less error-prone than direct iteration using `for...of`.
    *   Cons:
        *   May have performance implications due to the overhead of calling a method on each array element.
*   **Direct iteration using `for...of```**: 
    *   Pros:
        *   More control over loop behavior and potential for better optimization by the JavaScript engine.
        *   Less reliance on built-in methods, which can lead to more predictable performance.
    *   Cons:
        *   May be less readable or more error-prone than using `forEach`.
*   **Other considerations:** 
    *   The choice between these two approaches may also depend on other factors like code maintainability, readability, and personal preference.

**Library usage:**

There are no libraries used in this benchmarking test case. It only involves standard JavaScript features.

**Special JavaScript feature or syntax:**

The `for...of` loop is a special syntax that allows iterating over arrays and other iterable objects. The `.forEach()` method is also a built-in JavaScript method for iterating over an array.

**Benchmark preparation code:**

The script preparation code `arr = [1,2,3,4,5]` initializes an array with five elements for the benchmark.

Related benchmarks:

Iteration through array; of vs forEach (version: 1)

Comparing performance of: of vs forEach

Created: 6 years ago by: Registered User

Jump to the latest result

of

forEach

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):