Benchmark: This site broken

Script Preparation code:

var array = [];
for (var i=0, t=10000; i<t; i++) {
    array.push(Math.round(Math.random() * t))
}
var t=0;

​x
 
var array = [];for (var i=0, t=10000; i<t; i++) {    array.push(Math.round(Math.random() * t))}var t=0;​

Tests:

for let

for (let i = 0; i < array.length; i++) {
  t += array[i];
}

 
for (let i = 0; i < array.length; i++) {  t += array[i];}

for var

for (var i = 0; i < array.length; i++) {
  t += array[i];
}

 
for (var i = 0; i < array.length; i++) {  t += array[i];}​

for let cached
let len=array.length; for (let i = 0; i < len; i++) { t += array[i]; }
let len=array.length;
for (let i = 0; i < len; i++) {
t += array[i];
}
for let cached (const)
const len=array.length; for (let i = 0; i < len; i++) { t += array[i]; }
const len=array.length;
for (let i = 0; i < len; i++) {
t += array[i];
}
for var cached
var len=array.length; for (var i = 0; i < len; i++) { t += array[i]; }
var len=array.length;
for (var i = 0; i < len; i++) {
t += array[i];
}
forEach
array.forEach(function(v, i) { t += v; });
array.forEach(function(v, i) {
t += v;
});

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Experimental features:

Memory measurements supported only in Chrome.
For precise memory measurements Chrome must be launched with --enable-precise-memory-info flag.
More information: Monitoring JavaScript Memory

Test case name	Result
for let
for var
for let cached
for let cached (const)
for var cached
forEach

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 15_4_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.4 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 15 on iOS 15.4.1

View result in a separate tab

Test name	Executions per second
for let	604.2 Ops/sec
for var	603.6 Ops/sec
for let cached	779.6 Ops/sec
for let cached (const)	818.5 Ops/sec
for var cached	790.5 Ops/sec
forEach	1101.9 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 4 months ago):

Let's break down the provided benchmark data.

Benchmark Purpose

The benchmark measures the performance of different JavaScript iteration methods in executing a simple calculation on an array of numbers. The goal is to determine which method is the fastest.

Iteration Methods Compared

The benchmark compares six different iteration methods:

for let: A traditional for loop with the let keyword for variable declaration.
for var: A traditional for loop with the var keyword for variable declaration.
for let cached (const): Similar to for let, but uses a constant variable declaration (const) instead of re-declaration on each iteration.
forEach: The Array.prototype.forEach() method, which calls a callback function once for each element in the array.

Pros and Cons of Each Approach

for let:
- Pros: More modern syntax, no need to declare variable before use, better scoping.
- Cons: May incur overhead due to re-declaration on each iteration.
for var:
- Pros: Legacy syntax, widely supported by older browsers.
- Cons: Outdated syntax, potential naming conflicts, and scope issues.
for let cached (const):
- Pros: Combines the benefits of modern syntax with a constant variable declaration for performance optimization.
- Cons: May require careful consideration of when to use const vs let.
forEach:
- Pros: Native method, optimized for iteration, and concise syntax.
- Cons: May incur overhead due to callback function execution, and less control over iteration logic.

Library Usage

There is no explicit library usage mentioned in the benchmark definition or test cases.

Special JavaScript Features or Syntax

No special features or syntax are used beyond what's already described above. However, it's worth noting that forEach method uses a callback function, which may incur additional overhead compared to traditional loops.

Alternative Benchmarks

Other alternatives for benchmarking iteration performance could include:

Using a more complex array operation (e.g., sorting, filtering)
Incorporating concurrency or parallelization
Comparing different JavaScript engines (e.g., V8, SpiderMonkey) or browsers
Adding noise or variability to the benchmark inputs to simulate real-world usage

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark data.

**Benchmark Purpose**

The benchmark measures the performance of different JavaScript iteration methods in executing a simple calculation on an array of numbers. The goal is to determine which method is the fastest.

**Iteration Methods Compared**

The benchmark compares six different iteration methods:

1. **for let**: A traditional `for` loop with the `let` keyword for variable declaration.
2. **for var**: A traditional `for` loop with the `var` keyword for variable declaration.
3. **for let cached (const)**: Similar to `for let`, but uses a constant variable declaration (`const`) instead of re-declaration on each iteration.
4. **forEach**: The `Array.prototype.forEach()` method, which calls a callback function once for each element in the array.

**Pros and Cons of Each Approach**

1. **for let**:
	* Pros: More modern syntax, no need to declare variable before use, better scoping.
	* Cons: May incur overhead due to re-declaration on each iteration.
2. **for var**:
	* Pros: Legacy syntax, widely supported by older browsers.
	* Cons: Outdated syntax, potential naming conflicts, and scope issues.
3. **for let cached (const)**:
	* Pros: Combines the benefits of modern syntax with a constant variable declaration for performance optimization.
	* Cons: May require careful consideration of when to use `const` vs `let`.
4. **forEach**:
	* Pros: Native method, optimized for iteration, and concise syntax.
	* Cons: May incur overhead due to callback function execution, and less control over iteration logic.

**Library Usage**

There is no explicit library usage mentioned in the benchmark definition or test cases.

**Special JavaScript Features or Syntax**

No special features or syntax are used beyond what's already described above. However, it's worth noting that `forEach` method uses a callback function, which may incur additional overhead compared to traditional loops.

**Alternative Benchmarks**

Other alternatives for benchmarking iteration performance could include:

* Using a more complex array operation (e.g., sorting, filtering)
* Incorporating concurrency or parallelization
* Comparing different JavaScript engines (e.g., V8, SpiderMonkey) or browsers
* Adding noise or variability to the benchmark inputs to simulate real-world usage

Related benchmarks:

This site broken (version: 0)

Comparing performance of: for let vs for var vs for let cached vs for let cached (const) vs for var cached vs forEach

Created: 2 years ago by: Registered User

Jump to the latest result

for let

for var

for let cached

for let cached (const)

for var cached

forEach

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 4 months ago):