Benchmark: const vs let vs var vs sloppy v2

Tests:

var
var nagg = new Map(); function send_nodeagg(aggr) {return aggr}; var nodeagg = {aggr: nagg, send: send_nodeagg, currdt: '', currhost: '', currmap: new Map()}; nodeagg.send(nodeagg.aggr);
let
let nagg = new Map(); function send_nodeagg(aggr) {return aggr}; let nodeagg = {aggr: nagg, send: send_nodeagg, currdt: '', currhost: '', currmap: new Map()}; nodeagg.send(nodeagg.aggr);
const
const nagg = new Map(); function send_nodeagg(aggr) {return aggr}; const nodeagg = {aggr: nagg, send: send_nodeagg, currdt: '', currhost: '', currmap: new Map()}; nodeagg.send(nodeagg.aggr);
sloppy
nagg = new Map(); function send_nodeagg(aggr) {return aggr}; nodeagg = {aggr: nagg, send: send_nodeagg, currdt: '', currhost: '', currmap: new Map()}; nodeagg.send(nodeagg.aggr);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
var
let
const
sloppy

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36

Browser/OS: Chrome 118 on Linux

View result in a separate tab

Test name	Executions per second
var	4843178.5 Ops/sec
let	4945812.5 Ops/sec
const	4939193.0 Ops/sec
sloppy	1406768.6 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The benchmark is designed to compare the performance of four different variable declarations in JavaScript: `var`, `let`, `const`, and "sloppy" (which we'll discuss later). The goal is to see which declaration type yields the best performance in a specific scenario.

**Variable Declarations Compared**

Here's a brief explanation of each variable declaration type:

1. **`var`**: The traditional, older way of declaring variables in JavaScript. Variables declared with `var` have function scope, meaning they are accessible throughout the entire function, regardless of block scope.
2. **`let`**: Introduced in ECMAScript 2015 (ES6), `let` is a block-scoped variable declaration. This means that variables declared with `let` are only accessible within the block (e.g., if-else statement, for loop) where they are declared.
3. **`const`**: Similar to `let`, but `const` declares a constant value that cannot be changed after initialization.
4. **"Sloppy"`**: This option is not part of the standard JavaScript syntax. It's likely an alternative declaration type that mimics the behavior of older JavaScript engines (e.g., V8 in older Chrome versions). Variables declared with "sloppy" also have function scope, but their performance might be lower compared to `var`.

**Pros and Cons**

Here are some general pros and cons for each variable declaration type:

* **`var`**:
	+ Pros: widely supported, high performance (due to function scope)
	+ Cons: can lead to global variable pollution, has block scope limitations
* **`let`**:
	+ Pros: improves code readability, reduces global variable pollution
	+ Cons: can have performance issues due to redeclarations and hoisting
* **`const`**:
	+ Pros: ensures constant values are not changed, improves code reliability
	+ Cons: has similar redeclaration issues as `let`, might affect performance
* **"Sloppy"`**:
	+ Pros: maintains compatibility with older JavaScript engines (e.g., V8)
	+ Cons: likely has lower performance compared to standard `var` declarations

**Library and Special JS Features**

In the provided test cases, we don't see any explicit library usage or special JavaScript features (e.g., async/await, closures). The code focuses solely on variable declaration differences.

**Alternative Options**

If you wanted to add more variables to the benchmark or experiment with different scenarios, some alternative options could be:

* **`let` and `const` together**: Compare performance between `let` and `const` declarations.
* **Other variable declarations**: Include `postfix` (e.g., `x++`) or `inline` (e.g., `var x = 5;`) for comparison.
* **Multiple loops or iterations**: Increase the complexity of the benchmark by adding multiple loops or iterations to see how each declaration type performs in more realistic scenarios.

Keep in mind that experimenting with different variable declarations and scenarios can help you better understand their performance characteristics, but it's essential to keep your benchmark focused on specific use cases to ensure accurate results.

Related benchmarks:

const vs let vs var vs sloppy v2 (version: 0)

Comparing performance of: var vs let vs const vs sloppy

Created: 2 years ago by: Guest

Jump to the latest result

var

let

const

sloppy

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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