Benchmark: Map vs Object 7 - MeasureThat.net

Script Preparation code:

var map = new Map();
var obj = {};

map.set('a', 5);
map.set('b', 5);
map.set('c', 5);
map.set('d', 5);
map.set('e', 5);
map.set('f', 5);
obj['a'] = 5;
obj['b'] = 5;
obj['c'] = 5;
obj['d'] = 5;
obj['e'] = 5;
obj['f'] = 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']; }

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

This benchmark does not have any results yet. Be the first one to run it!

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 various components.

**Benchmark Definition**

The provided JSON represents a JavaScript microbenchmark, which is a small program designed to measure the performance of specific JavaScript code snippets. The benchmark is defined by:

* **Name**: A unique identifier for the benchmark.
* **Description**: A brief explanation of what the benchmark tests (in this case, lookup of a map vs an object).
* **Script Preparation Code**: The initial setup code executed before running the benchmark. In this case, it creates two data structures: `map` and `obj`, both populated with 7 key-value pairs. This code is executed to ensure that both data structures are ready for use.
* **Html Preparation Code**: An empty string, indicating that no HTML preparation code is required.

**Individual Test Cases**

The benchmark consists of two test cases:

1. **Map Lookup**: The first test case measures the performance of iterating over a map and using `map.get('a')` to retrieve a value.
2. **Object Lookup**: The second test case measures the performance of iterating over an object and using `obj['a']` to retrieve a value.

**Library and Features**

Both test cases use built-in JavaScript features:

* No external libraries are used in this benchmark.
* No special JavaScript features or syntax (e.g., async/await, Promises) are utilized in the test code.

**Options Compared**

The two test cases compare the performance of using a `Map` data structure (`map.get('a')`) versus an object (`obj['a']`). Both approaches iterate over the same key-value pairs, but with different internal implementation details.

* **Map**: JavaScript maps are implemented as hash tables, which provide fast lookups (average O(1) time complexity). Maps also support iteration using `for...of` loops.
* **Object**: JavaScript objects are implemented as arrays of keys, which require slower lookups (average O(n) time complexity). Objects do not support iteration in the same way as maps; instead, they use property access (`obj['a']`) or the `for...in` loop.

**Pros and Cons**

Here's a brief summary:

* **Map Lookup**:
	+ Pros: Fast lookups (average O(1) time complexity).
	+ Cons: May have higher overhead due to the creation of a map object.
* **Object Lookup**:
	+ Pros: No additional object creation overhead.
	+ Cons: Slower lookups (average O(n) time complexity).

**Other Alternatives**

If you wanted to modify this benchmark, you could consider adding other test cases that compare:

* Using `Array.prototype.indexOf()` instead of property access (`obj['a']`).
* Using `for...in` loop for object iteration.
* Implementing a custom lookup data structure (e.g., a binary search tree).

Keep in mind that these alternatives would require changes to the benchmark's script preparation code and test cases.

Related benchmarks:

Map vs Object 7 (version: 0)

Lookup of map vs object

Comparing performance of: Map lookup vs Obj lookup

Created: 3 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):