Benchmark: Best practise for loop, with more options

Script Preparation code:


var names = ['George','Ringo','Paul','John','George','Ringo','Paul','John','George','Ringo','Paul','John','George','Ringo','Paul','John','George','Ringo','Paul','John','George','Ringo','Paul','John'];
var total = 0;

Tests:

best practice
for(var i=0,j=names.length;i<j;i++){ total++ }
normal
for(var i=0; i<names.length;i++){ total++; }
best practice with plus plus reversed
for(var i=0,j=names.length;i<j;i++){ total++ }
normal with plus plus reversed
for(var i=0; i<names.length;++i){ total++; }
backwards
for(var i=names.length-1;i>=0;i--){ total++ }
backwards minus minus reversed
for(var i=names.length-1;i>=0;--i){ total++ }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
best practice
normal
best practice with plus plus reversed
normal with plus plus reversed
backwards
backwards minus minus reversed

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

The benchmark you provided tests different approaches for iterating over an array in a `for` loop. The goal is to determine which method is most efficient.

**Benchmark Definitions:**

1. **Best Practice:** `for(var i=0,j=names.length;i<j;i++){\r\n  total++\r\n}`
2. **Normal:** `for(var i=0; i<names.length;i++){\r\n  total++;\r\n}`
3. **Best Practice with Plus Plus Reversed:** `for(var i=names.length-1;i>=0;++i){\r\n  total++\r\n}`
4. **Normal with Plus Plus Reversed:** `for(var i=names.length-1;i>=0;--i){\r\n  total++\r\n}`
5. **Backwards:** `for(var i=names.length-1;i>=0;i--){\r\n  total++\r\n}`
6. **Backwards Minus Minus Reversed:** `for(var i=names.length-1;i>=0;--i){\r\n  total++\r\n}`

**Options Compared:**

The benchmark compares the performance of six different approaches:

* Best Practice with explicit increment (`i++`)
* Normal with explicit increment (`i++`)
* Best Practice with implicit increment (`i--;`) and plus plus reversed
* Normal with implicit increment (`--i`) and plus plus reversed
* Backwards iteration using decrement (`--i`)
* Backwards iteration using minus minus reversal (`--i`)

**Pros and Cons:**

1. **Best Practice:** This approach is generally considered best practice for iterating over arrays in JavaScript. It avoids the issues with implicit increment and plus plus reversal.
2. **Normal:** This approach is simple and easy to read, but it can lead to problems if not used carefully (e.g., when working with array indices).
3. **Best Practice with Plus Plus Reversed:** While this approach may seem similar to the Best Practice method, using implicit increment (`--i`) can lead to issues with performance and code readability.
4. **Normal with Plus Plus Reversed:** Similar to the previous point, using plus plus reversal in a `for` loop can be problematic and lead to unexpected behavior.
5. **Backwards:** Iterating over an array in reverse order can be useful in certain situations, but it may not always be the most efficient approach.

**Library/Feature Usage:**

None of the benchmark definitions explicitly use any JavaScript libraries or features beyond basic `for` loops.

**Special JS Features/Syntax:**

No special JavaScript features or syntax are used in these benchmark definitions. The focus is solely on iterating over an array using a `for` loop.

**Other Alternatives:**

If you're interested in exploring other iteration methods, here are a few alternatives:

* **While Loop:** Instead of using a `for` loop, you can use a `while` loop to iterate over the array. This approach can be more flexible and easier to read in certain situations.
* **Array.forEach():** JavaScript provides an array method called `forEach()` that allows you to iterate over arrays without explicit loops. This approach is often considered more concise and readable than traditional `for` loops.

In conclusion, this benchmark helps determine which iteration method (Best Practice or Normal) is most efficient in JavaScript, while also exploring the implications of using plus plus reversal and implicit increment.

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.198 Safari/537.36

Browser/OS: Chrome 86 on Windows

View result in a separate tab

Test name	Executions per second
best practice	163386.1 Ops/sec
normal	95191.7 Ops/sec
best practice with plus plus reversed	130826.6 Ops/sec
normal with plus plus reversed	96383.7 Ops/sec
backwards	139859.1 Ops/sec
backwards minus minus reversed	137577.9 Ops/sec

Related benchmarks:

Best practise for loop, with more options (version: 0)

Comparing performance of: best practice vs normal vs best practice with plus plus reversed vs normal with plus plus reversed vs backwards vs backwards minus minus reversed

Created: 5 years ago by: Guest

Jump to the latest result

best practice

normal

best practice with plus plus reversed

normal with plus plus reversed

backwards

backwards minus minus reversed

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):