Benchmark: for of loop - MeasureThat.net

Script Preparation code:

var testArray = Array(10000);

Tests:

for n
const l = testArray.length; for ( let n=0; n < l; ++n) if ( testArray[n] === "$" ) continue;
for of ..
for ( const n of testArray) if ( n === "$" ) continue;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for n
for of ..

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark definition and test cases.

**Benchmark Definition**

The benchmark is designed to compare two approaches for iterating over an array: traditional `for` loop with incrementing index (`n`) versus the newer `for...of` loop syntax.

**Script Preparation Code**

Before running each test case, a script prepares the environment:

```javascript
var testArray = Array(10000);
```

This creates an array of 10,000 elements and assigns it to the `testArray` variable.

**Html Preparation Code**

There is no HTML preparation code provided, which means that this benchmark only measures JavaScript execution performance and does not account for any overhead from rendering or displaying HTML content.

**Test Cases**

There are two individual test cases:

1. **"for n"`**

This test case uses a traditional `for` loop with incrementing index (`n`) to iterate over the array:
```javascript
for (let n = 0; n < l; ++n) {
    if (testArray[n] === "$") continue;
}
```
In this code, `l` is the length of the `testArray`, which was calculated earlier. The loop iterates from index 0 to the length of the array, incrementing `n` by 1 on each iteration.

2. **"for of .."`**

This test case uses the new `for...of` loop syntax to iterate over the array:
```javascript
for (const n of testArray) {
    if (n === "$") continue;
}
```
In this code, the `for...of` loop iterates directly over the elements of the `testArray`, assigning each element to the variable `n`. The rest of the code is similar to the traditional `for` loop.

**Library and Features**

There are no external libraries used in these test cases. However, it's worth noting that the `for...of` loop syntax was introduced in ECMAScript 2015 (ES6) and provides a more concise way to iterate over arrays and other iterable objects.

**Browser and Device Information**

The latest benchmark results show two browsers running on different devices:

1. **Firefox 117**: This browser is running on a desktop Linux system, with an execution rate of approximately 45249 executions per second.
2. **Firefox 117**: This same browser is running on the same device, but with a different test case ("for of .."), resulting in an execution rate of approximately 9876 executions per second.

**Pros and Cons**

Here's a brief analysis of the pros and cons of each approach:

* Traditional `for` loop:
	+ Pros: more control over iteration, easier to understand for developers familiar with older JavaScript versions.
	+ Cons: can be less efficient than `for...of`, requires manual index calculation and incrementing.
* `for...of` loop:
	+ Pros: concise, expressive syntax, reduces chance of errors related to index management.
	+ Cons: may require more time to understand for developers unfamiliar with the new syntax.

**Other Alternatives**

If you're interested in exploring alternative benchmarking scenarios or test cases, consider these:

* Using different data structures (e.g., objects, sets, maps)
* Incorporating additional libraries or frameworks
* Experimenting with different iteration patterns (e.g., while loops, recursive functions)

These variations can help you gain a deeper understanding of the performance characteristics of each approach and identify potential optimization opportunities in your own code.

Related benchmarks:

for of loop (version: 0)

for item of array v.s. for n=0;n<array.length;++n

Comparing performance of: for n vs for of ..

Created: 3 years ago by: Guest

Jump to the latest result

for n

for of ..

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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