Benchmark: Map vs Object 1 - MeasureThat.net

Script Preparation code:

var map = new Map();
var obj = {};

map.set('a', 5);
obj['a'] = 5;

var i = 0, count = 100000, 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']; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Map lookup
Obj lookup

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.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks to compare the performance of different approaches. The provided benchmark measures the execution time of two types of lookups: Map lookup and Object lookup.

**Tested Options**

The benchmark compares two options:

1. **Map Lookup**: This option uses the `Map` data structure in JavaScript, which is a built-in object that stores key-value pairs.
2. **Object Lookup**: This option uses the built-in object literal syntax to create an object and store a value under a key.

**Pros and Cons**

* **Map Lookup**:
	+ Pros: Maps are designed for fast lookups, with an average time complexity of O(1).
	+ Cons: Maps require more memory than objects, as they need to store the underlying array.
* **Object Lookup**:
	+ Pros: Objects are lightweight and don't require extra memory.
	+ Cons: Object lookup has a time complexity of O(n), where n is the number of properties in the object. This can be slower for large datasets.

**Library Usage**

The benchmark uses the `Map` class from JavaScript's built-in API, which is part of the ECMAScript standard. The purpose of this library is to provide a fast and efficient way to store key-value pairs.

**Special JS Feature/Syntax**

This benchmark does not use any special JavaScript features or syntax, making it accessible to a wide range of developers.

**Other Alternatives**

If you're looking for alternative data structures for lookups, you could consider:

1. **Arrays**: While arrays are not optimized for lookups, they can be used as an alternative. However, this would likely result in slower performance compared to Maps or objects.
2. **Data Structures like `WeakMap`**: WeakMaps are another type of Map implementation that uses a weak reference to store key-value pairs, making it useful for scenarios where the map is not needed to prevent memory leaks.

**Benchmark Preparation Code**

The provided benchmark preparation code creates an empty Map and object, sets a value under a key in each, and then declares a variable `a` that will be used in the test cases. The HTML preparation code is empty, indicating that no additional setup is required for the benchmark.

**Individual Test Cases**

The benchmark consists of two individual test cases:

1. **Map Lookup**: This test case iterates over a loop 100,000 times and retrieves the value associated with the key `'a'` using `map.get('a')`.
2. **Object Lookup**: This test case iterates over a loop 100,000 times and retrieves the value associated with the key `'a'` using `obj['a']`.

The results of each test case are stored in the `ExecutionsPerSecond` field of the benchmark result, which provides an estimate of how many executions per second can be achieved for each option.

Related benchmarks:

Map vs Object 1 (version: 0)

Lookup of map vs object

Comparing performance of: Map lookup vs Obj lookup

Created: 4 years ago by: Guest

Jump to the latest result

Map lookup

Obj lookup

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):