Benchmark: Caching values in Array vs. Caching values in Object

Script Preparation code:

var objectArray = new Array(10000).fill(null);
var arrayArray = new Array(10000).fill(null);
var prefilledArray = Array.from(new Array(3), () => new Array(3))
var preinitializedArray = new Array(10000);

Tests:

Object Saving
const a = 100; const b = "string"; const c = { a: 1000, b: "objectString"} for(const [index, ] of objectArray.entries()) { objectArray[index] = { a, b, c }; }
Array Saving
const a = 100; const b = "string"; const c = { a: 1000, b: "objectString"} for(const [index, ] of arrayArray.entries()) { arrayArray[index] = [ a, b, c ]; }
Prefilled Array Saving
const a = 100; const b = "string"; const c = { a: 1000, b: "objectString"} for(const [index, ] of prefilledArray.entries()) { prefilledArray[index][0] = a; prefilledArray[index][1] = b; prefilledArray[index][2] = c; }
Preinitialized Array Saving
const a = 100; const b = "string"; const c = { a: 1000, b: "objectString"} preinitializedArray = Array.from(preinitializedArray, () => new Array(3)); for(const [index, ] of preinitializedArray.entries()) { preinitializedArray[index][0] = a; preinitializedArray[index][1] = b; preinitializedArray[index][2] = c; }
PreinitializedArray V2
const a = 100; const b = "string"; const c = { a: 1000, b: "objectString"} preinitializedArray = Array.from(preinitializedArray, () => [ , , ]); for(const [index, ] of preinitializedArray.entries()) { preinitializedArray[index][0] = a; preinitializedArray[index][1] = b; preinitializedArray[index][2] = c; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object Saving
Array Saving
Prefilled Array Saving
Preinitialized Array Saving
PreinitializedArray V2

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/112.0.0.0 Safari/537.36 Edg/112.0.1722.64

Browser/OS: Chrome 112 on Windows

View result in a separate tab

Test name	Executions per second
Object Saving	803.5 Ops/sec
Array Saving	782.7 Ops/sec
Prefilled Array Saving	1120347.4 Ops/sec
Preinitialized Array Saving	166.3 Ops/sec
PreinitializedArray V2	217.6 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided benchmark, created on MeasureThat.net, compares the performance of caching values in two different data structures: arrays and objects. The test measures how long it takes for each approach to save and update 10,000 elements.

**Data Structures Compared**

There are four test cases:

1. **Object Saving**: Caching values in an object (`objectArray`).
2. **Array Saving**: Caching values in an array (`arrayArray`).
3. **Prefilled Array Saving**: Creating a prefilled array with 10,000 elements and then saving and updating values in it (`prefilledArray`).
4. **Preinitialized Array V2**: Initializing an array with 10,000 elements, each containing three empty arrays, and then saving and updating values in it (`preinitializedArrayV2`).

**Approach Comparison**

Here's a brief overview of each approach:

* **Object Saving**: Storing key-value pairs in an object. When the object grows large, finding a specific value can become slow due to the need to traverse the object's properties.
* **Array Saving**: Storing values in an array. Arrays are generally faster than objects for random access, but they can be slower when dealing with complex data structures or frequent inserts/deletes.
* **Prefilled Array Saving**: Creating a prefilled array and then saving and updating values in it. This approach takes advantage of the existing array structure to reduce overhead.
* **Preinitialized Array V2**: Initializing an array with 10,000 elements, each containing three empty arrays. This approach is similar to the previous one but uses nested arrays instead.

**Pros and Cons**

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

* **Object Saving**:
	+ Pros: Easy to implement, flexible data structure.
	+ Cons: Slow for large objects due to property traversal.
* **Array Saving**:
	+ Pros: Fast random access, simple implementation.
	+ Cons: Limited flexibility, may require explicit bounds checking.
* **Prefilled Array Saving**:
	+ Pros: Reduces overhead by reusing existing array structure.
	+ Cons: Requires significant upfront memory allocation.
* **Preinitialized Array V2**:
	+ Pros: Combines benefits of prefilled arrays with nested arrays.
	+ Cons: More complex implementation, may require additional memory allocation.

**Library Usage**

There is no explicit library usage mentioned in the benchmark definition or test cases. However, JavaScript's built-in `Array` and `Object` data structures are used throughout the tests.

**Special JS Features or Syntax**

No special JavaScript features or syntax are mentioned in the benchmark definition or test cases. The code uses standard ECMAScript 2022 features.

**Alternatives**

For large-scale performance-critical applications, alternative approaches to caching values in arrays and objects might include:

* **Using optimized data structures**, such as custom buffers or fixed-size arrays.
* **Employing caching mechanisms**, like memoization or caching libraries.
* **Utilizing parallel processing**, if the workloads can be divided among multiple threads or cores.

Please note that these alternatives are not necessarily applicable to this specific benchmark, which focuses on simple caching performance.

Related benchmarks:

Caching values in Array vs. Caching values in Object (version: 0)

Comparing performance of: Object Saving vs Array Saving vs Prefilled Array Saving vs Preinitialized Array Saving vs PreinitializedArray V2

Created: one year ago by: Guest

Jump to the latest result

Object Saving

Array Saving

Prefilled Array Saving

Preinitialized Array Saving

PreinitializedArray V2

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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