Benchmark: [aech0Xod] Map vs Object

Script Preparation code:

var map = new Map();
var obj = {};

map.set('a', 5);
obj['a'] = 5;

var i = 0, count = 1000, a;

Tests:

Map lookup
for (i = 0; i < count; i++) { a = map.get('a'); }
Obj lookup
for (i = 0; i < count; i++) { a = obj['a']; }
Map delete
for (i = 0; i < count; i++) { map.delete('a'); }
Obj delete
for (i = 0; i < count; i++) { delete obj['a']; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Map lookup
Obj lookup
Map delete
Obj delete

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.

I'll break down the benchmark and explain what's being tested, compared options, pros/cons, and other considerations.

**Benchmark Overview**

The test is comparing the performance of two data structures in JavaScript: `Map` and objects (`{}`). The test involves creating a map and an object, setting key-value pairs, and then performing lookups and deletes on both data structures. The goal is to determine which one performs better.

**Comparison Options**

There are four tests:

1. **Map lookup**: Iterating over the map using `map.get()` to retrieve a value.
2. **Object lookup**: Iterating over an object using bracket notation (`obj['a']`) to retrieve a value.
3. **Map delete**: Iterating over the map using `map.delete()` to remove a key-value pair.
4. **Object delete**: Iterating over an object using `delete` keyword to remove a property.

**Pros and Cons**

1. **Map**:
	* Pros: Map is designed for fast lookups, provides iterators, and supports hash collisions.
	* Cons: May have slower initial creation time compared to objects, and may not be as widely supported in older browsers.
2. **Objects (bracket notation)**:
	* Pros: Widely supported across all browsers, objects are lightweight, and bracket notation is simple.
	* Cons: Bracket notation can lead to slower lookups, especially for large datasets.

**Other Considerations**

1. **Library usage**: Neither `Map` nor object properties use any external libraries. The performance difference between the two is directly related to the underlying implementation of these data structures in JavaScript engines.
2. **Special JS features**: There are no special JavaScript features or syntax used in this benchmark, making it accessible to a wide range of developers.

**Alternative Approaches**

Other approaches that could be used for similar benchmarks include:

1. Using `Array.prototype.forEach()` and accessing elements by index (e.g., `arr[i]`) instead of using bracket notation.
2. Creating an array of objects or a map-like object (using `Object.create()`, for example) to compare performance with the standard `Map` and objects approach.
3. Utilizing more advanced data structures like sets, queues, or trees to create additional benchmarks.

These alternatives can help developers explore different aspects of JavaScript's built-in data structures and optimize their code for specific use cases.

Related benchmarks:

[aech0Xod] Map vs Object (version: 0)

map vs object

Comparing performance of: Map lookup vs Obj lookup vs Map delete vs Obj delete

Created: 3 years ago by: Guest

Jump to the latest result

Map lookup

Obj lookup

Map delete

Obj delete

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):