Benchmark: Map vs Object (get) [2]

Script Preparation code:

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

Tests:

Obj
for(let i = 0; i < count; i ++){ sum += obj[key]; }
Map
for(let i = 0; i < count; i ++){ sum += map.get(key); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Obj
Map

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.0 Safari/605.1.15

Browser/OS: Safari 14 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Obj	2116.1 Ops/sec
Map	2097.4 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what is being tested, compared, and discussed.

**Benchmark Overview**

The benchmark measures the performance difference between using an object (`obj`) to store data versus using a `Map` data structure in JavaScript. Specifically, it compares the execution time of adding 1000 values to each data structure and then iterating over them to sum up their values.

**Options Compared**

Two options are compared:

1. **Object (get)**: This option uses an object (`obj`) to store data, where a key-value pair is created by setting `obj[key] = 5`. The benchmark then iterates over the object using a loop to add up the sum of its values.
2. **Map**: This option uses a `Map` data structure to store data, where a key-value pair is created by setting `map.set(key, 5)`. The benchmark then iterates over the map using a loop to add up the sum of its values.

**Pros and Cons of Each Approach**

**Object (get)**

Pros:

* Simple and easy to understand
* Familiar syntax for many developers

Cons:

* Performance may be slower due to the overhead of accessing properties on an object
* May lead to slower iteration over large datasets

**Map**

Pros:

* More efficient than objects for storing large amounts of data, as it uses a hash table for fast lookups
* Provides additional features like set operations and map size

Cons:

* May be less familiar syntax for some developers
* Requires importing the `Map` class from the `util` module in older browsers (not applicable in modern browsers)

**Library and Purpose**

In this benchmark, the `util` module is imported to use the `Map` class. The `Map` data structure provides a more efficient way to store and access large amounts of key-value pairs.

**Special JS Feature or Syntax**

None mentioned explicitly, but it's worth noting that the benchmark uses modern JavaScript syntax (e.g., `let`, arrow functions, template literals) and assumes a modern browser environment. If this were run in an older browser, additional modifications might be needed to accommodate differences in behavior or features.

**Other Alternatives**

In addition to using objects and maps, other data structures could be used to store the same type of data, such as:

* Arrays: While not ideal for this specific use case, arrays could be used if the data is already sorted or has a predictable structure.
* Sets: Similar to maps, sets provide fast lookups but with only unique values; however, they would not provide the same level of value association as a map.

In summary, the benchmark highlights the performance difference between using objects and `Map` data structures for storing and iterating over large datasets in JavaScript.

Related benchmarks:

Map vs Object (get) [2] (version: 1)

Comparing performance of: Obj vs Map

Created: 4 years ago by: Registered User

Jump to the latest result

Obj

Map

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):