Benchmark: Map vs Object part 2

Script Preparation code:

var map = new Map();
var obj = {};
let a;
for (let i = 0;i < 100000; i++) {
	map.set(`${i}`, i);
  	obj[`${i}`] = i;
}

Tests:

Map lookup
for (let i = 0; i < 10000; i++) { a = map.get(`${i}`); }
Obj lookup
for (let i = 0; i < 10000; i++) { a = obj[`${i}`]; }

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 dive into the world of JavaScript microbenchmarks on MeasureThat.net.

The benchmark being tested is a comparison between two data structures: Maps and Objects for storing and retrieving values by key. The test cases are designed to simulate common use scenarios, such as looking up values by index.

**Script Preparation Code**

The script preparation code initializes two variables:

1. `map`: an empty Map object.
2. `obj`: an empty Object literal (`{}`).
3. A loop that sets 100,000 key-value pairs for both `map` and `obj`, using string keys with the format `"i"` (e.g., `"0"`, `"1"`, etc.).

The purpose of this setup is to create a large dataset that can be used as input for the test cases.

**Test Cases**

There are two individual test cases:

### Map Lookup

```javascript
for (let i = 0; i < 10000; i++) {
  const value = map.get(`${i}`);
}
```

This test case iterates 10,000 times and retrieves values from the `map` using the `get()` method. The goal is to measure how fast this operation can be performed.

### Object Lookup

```javascript
for (let i = 0; i < 10000; i++) {
  const value = obj[`${i}`];
}
```

This test case also iterates 10,000 times and retrieves values from the `obj` using bracket notation (`[]`). Again, the goal is to measure how fast this operation can be performed.

**Comparison of Approaches**

The two approaches differ in their data structure and lookup method:

1. **Map Lookup**: Uses a Map object with the `get()` method. Maps are designed for fast lookups by key, making them ideal for scenarios where you need to quickly retrieve values associated with a specific key.
2. **Object Lookup**: Uses an Object literal (`{}`) with bracket notation (`[]`). While this approach is also suitable for simple lookups, it may not be as efficient as using a Map object.

**Pros and Cons**

Pros of Map Lookup:

* Fast lookups by key
* Efficient use of memory

Cons of Map Lookup:

* Requires the `get()` method, which may incur additional overhead

Pros of Object Lookup:

* Simple to implement
* Familiar syntax for many developers

Cons of Object Lookup:

* May not be as efficient as using a Map object

**Library and Purpose**

In this benchmark, no specific library is used. However, in general, libraries like Lodash or Ramda provide optimized implementations of data structures and lookup methods that can improve performance.

**Special JS Feature or Syntax**

None are mentioned in the provided code snippets.

**Alternatives**

Other alternatives for data structures and lookup methods include:

* Using a custom Array or Buffer implementation
* Utilizing a third-party library like Moment.js for date-related lookups
* Leveraging modern JavaScript features like `Object.getPrototypeOf()` or `Map.prototype.has()`

Related benchmarks:

Map vs Object part 2 (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):