Benchmark: Array loop vs foreach vs map vs for of1234

Script Preparation code:

   var arr = [];
    for (var i = 0; i < 1000; i++) {
      arr[i] = i;
    }
  
    function someFn(i) {
      return i * 3 * 8;
    }

var n= 0;

Tests:

foreach
arr.forEach(function (item){ })
for
for (var i = 0, len = arr.length; i < len; i++) { n = arr[i] }
for of
for (var n of arr) { }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
foreach
for
for of

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):

LLMs can make mistakes. Check important info.

I'll provide an explanation of the benchmark, its options, pros and cons, and other considerations.

**What is being tested?**

MeasureThat.net tests the performance of different JavaScript iteration methods: `forEach`, traditional `for` loop, and `for...of` loop. The test case creates a large array (`arr`) with 1000 elements and assigns each element an index `i`. Then it defines a function `someFn(i)` that takes an argument `i` and returns the result of multiplying `i` by 3 and 8.

**Options being compared**

The three options being tested are:

1. **forEach**: This method iterates over the array using a callback function.
2. **Traditional for loop**: This method uses a manual index variable `i` to iterate over the array.
3. **for...of loop**: This method is a newer, more concise way of iterating over arrays and objects.

**Pros and cons of each approach**

1. **forEach**:
	* Pros: Easy to read and write, no explicit indexing required.
	* Cons: May incur additional overhead due to the callback function.
2. **Traditional for loop**:
	* Pros: Direct control over iteration, no additional overhead from callbacks.
	* Cons: More verbose code, requires manual indexing.
3. **for...of loop**:
	* Pros: Concise and readable, minimal overhead.
	* Cons: Limited support on older browsers, may not work as expected with array iterators.

**Library used**

There is no explicit library mentioned in the benchmark definition or test cases. However, it's likely that the benchmarking framework uses a built-in JavaScript engine to execute the test code.

**Special JS feature or syntax**

There are no special features or syntaxes mentioned in the benchmark. All three iteration methods are standard part of the JavaScript language.

**Other considerations**

The benchmark seems to focus on measuring the performance differences between these three iteration methods, rather than exploring other aspects of JavaScript, such as error handling or type coercion.

**Alternative approaches**

If you were to write your own benchmarking tool for iterating over arrays in JavaScript, you might consider the following alternatives:

1. **Using a custom iterator**: Instead of relying on built-in iteration methods, you could create a custom iterator that implements a specific iteration strategy.
2. **Using a profiler**: Profilers can provide more detailed information about the execution time and resource usage of different parts of your code.
3. **Writing microbenchmarks for specific scenarios**: You might write separate benchmarks for specific scenarios, such as iterating over large arrays or objects with complex structures.

Overall, MeasureThat.net provides a useful example of benchmarking iteration methods in JavaScript, highlighting the trade-offs between different approaches and allowing users to compare their performance on modern browsers.

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.121 Safari/537.36

Browser/OS: Chrome 85 on Windows

View result in a separate tab

Test name	Executions per second
foreach	1015795.2 Ops/sec
for	3556.1 Ops/sec
for of	522801.7 Ops/sec

Related benchmarks:

Array loop vs foreach vs map vs for of1234 (version: 0)

Comparing performance of: foreach vs for vs for of

Created: 4 years ago by: Guest

Jump to the latest result

foreach

for

for of

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):