Benchmark: Map vs Object Set

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++) { map.set('a'+i, Math.random()); }
Obj lookup
for (i = 0; i < count; i++) { obj['a'+i] = Math.random(); }

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:

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data and explain what is tested, compared, and other considerations.

**Benchmark Definition**

The benchmark definition provides the setup for two test cases:

1. `map.set('a'+i, Math.random());`: This line of code sets a key-value pair in the Map object, where the key is a string generated by concatenating 'a' with an integer `i`. The value is a random number generated using `Math.random()`.
2. `obj['a'+i] = Math.random();`: This line of code sets a property on the Object object using the same syntax as in 1, but without creating a new Map instance.

**Options Compared**

The benchmark compares two approaches:

A) Using a Map ( `map.set()` )
B) Using an Object ( `obj['a'+i] = ...` )

**Pros and Cons of Each Approach**

**Map ( A )**

Pros:

* Maps are designed for key-value pairs, making it easier to access and manipulate data.
* Maps have a faster lookup time compared to Objects in JavaScript.

Cons:

* Creating a new Map instance is more memory-intensive than creating an Object instance.
* Some operations on Maps can be slower due to the overhead of managing keys and values.

**Object ( B )**

Pros:

* Creating an Object instance is less memory-intensive than creating a Map instance.
* Some operations on Objects are faster since they don't require key-value pair management.

Cons:

* Objects are not designed for key-value pairs, making it harder to access and manipulate data.

**Other Considerations**

In this benchmark, the test cases only focus on the performance difference between using Maps and Objects. However, there might be other considerations depending on the specific use case, such as:

* Memory usage: Which approach consumes more memory?
* Code complexity: Which approach requires more complex code to achieve the same result?

**Library Usage**

In this benchmark, no libraries are explicitly mentioned. However, JavaScript engines like V8 (used by Chrome and Node.js) have their own internal data structures that might be used under the hood.

**Special JS Feature or Syntax**

There is no special JS feature or syntax mentioned in this benchmark.

Now, let's look at some alternative approaches:

Other alternatives to compare in a similar benchmark could include:

* Using Arrays instead of Maps and Objects
* Using JSON objects instead of plain JavaScript objects
* Using custom data structures like Sets, Queues, or Trees

However, these alternatives might not be as relevant for this specific benchmark, which focuses on the performance difference between using Maps and Objects.

Related benchmarks:

Map vs Object Set (version: 0)

Set 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):