Benchmark: forEach vs for..loop dynamic length

Script Preparation code:

var gsmCells = [
        {
            "countrycode": 250,
            "operatorid": 2,
            "lac": 9703,
            "cellid": 23446,
            "signal_strength": -75
        },
        {
            "countrycode": 250,
            "operatorid": 2,
            "lac": 9703,
            "cellid": 59141,
            "signal_strength": -76
        },
        {
            "countrycode": 250,
            "operatorid": 2,
            "lac": 9703,
            "cellid": 6924,
            "signal_strength": -80
        },
        {
            "countrycode": 250,
            "operatorid": 2,
            "lac": 9703,
            "cellid": 23449,
            "signal_strength": -81
        }
    ];

Tests:

reduce
let max = gsmCells[0]; gsmCells.forEach( (element, index) => { if(element.signal_strength > max.signal_strength) max = element; } )
for
let max = gsmCells[0]; for(let i = 0; i < gsmCells.length; i++){ if(gsmCells[i].signal_strength > max.signal_strength) max = gsmCells[i]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
reduce
for

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36

Browser/OS: Chrome 122 on Windows

View result in a separate tab

Test name	Executions per second
reduce	7176680.5 Ops/sec
for	1786164.6 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided benchmark measures the performance of two approaches to find the maximum signal strength in an array: `forEach` with arrow function and `for` loop with dynamic length.

**Test Case 1: `forEach` with Arrow Function**

In this test case, the `forEach` method is used to iterate over the `gsmCells` array. The callback function takes two arguments: `element` (the current array element) and `index` (the index of the current element). Inside the loop, it checks if the signal strength of the current element is greater than the maximum signal strength found so far (`max`). If true, it updates the `max` variable.

**Pros:**

* The `forEach` method is a concise way to iterate over arrays.
* It's often more readable and maintainable than traditional `for` loops.
* It allows for easy modification of the iteration logic without changing the loop structure.

**Cons:**

* The `forEach` method can be slower than traditional `for` loops, especially for large arrays.
* It creates a new scope for each iteration, which can lead to performance overhead.

**Test Case 2: `for` Loop with Dynamic Length**

In this test case, a traditional `for` loop is used to iterate over the `gsmCells` array. The loop iterates over the indices of the array using the `length` property, and checks if the signal strength of each element is greater than the maximum signal strength found so far (`max`). If true, it updates the `max` variable.

**Pros:**

* Traditional `for` loops are often faster than `forEach` methods.
* They can be more efficient for large arrays, as they avoid creating new scopes.

**Cons:**

* The loop structure can become complex and harder to read with multiple conditions and iterations.
* It may require more maintenance and updates compared to the concise `forEach` method.

**Library Used: None**

The test cases do not use any external libraries or dependencies. They only rely on the built-in JavaScript `forEach` method and traditional `for` loops.

**Special JS Feature/ Syntax: None**

There are no special JavaScript features or syntax used in these test cases.

**Other Alternatives**

If you want to optimize this benchmark, consider using:

* **Iterators**: Instead of using `forEach`, you can create an iterator over the array and iterate manually.
* **Array.prototype.map()`: You can use `map()` instead of `forEach` for the same purpose, but it may have different performance characteristics.
* **Native Web Workers**: If you need to process large arrays in parallel, consider using web workers to take advantage of multi-core processors.

To modify or extend this benchmark, you can:

* Increase or decrease the size of the `gsmCells` array to see how performance scales.
* Use different data types or values for the signal strength property.
* Add more test cases or variations to compare the performance differences.

Related benchmarks:

forEach vs for..loop dynamic length (version: 0)

Comparing performance of: reduce vs for

Created: 2 years ago by: Registered User

Jump to the latest result

reduce

for

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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