Benchmark: map vs object - key access 3

Script Preparation code:

var items = Array.from(Array(100000), (_, x) => ({
    key: x,
    value: x * 10
}));

var objContainer = {};
var mapContainer = new Map();

for (let i = 10000; i >= 0; i--) {
    const index = Math.floor(Math.random() * 100000);
    const item = items[index];
    objContainer[item.key] = item;
    mapContainer.set(item.key, item)
}

Tests:

Object access
items.forEach(item => objContainer[item.value])
Map get
items.forEach(item => mapContainer.get(item.value))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object access
Map get

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

**Benchmark Definition:**

The provided JSON represents a benchmark definition that tests two different approaches:

1. **Object Access:** `items.forEach(item => objContainer[item.value])`
2. **Map Get:** `items.forEach(item => mapContainer.get(item.value))`

These test cases are designed to measure the performance difference between accessing an object's value using its key and accessing a Map's value using its key.

**Options Compared:**

The two options being compared are:

1. **Object Access**: Using the bracket notation (`objContainer[item.value]`) to access an object's value.
2. **Map Get**: Using the `get()` method of the Map data structure to access its value.

**Pros and Cons:**

* **Object Access**:
	+ Pros:
		- Fast lookup times, as objects are hash tables that allow for direct access to values using their keys.
		- Can be more readable and intuitive for developers familiar with object notation.
	+ Cons:
		- May not perform well if the object is very large or has a lot of duplicate keys.
		- May not handle collisions (multiple objects with the same key) as efficiently as Maps.
* **Map Get**:
	+ Pros:
		- Handles collisions more efficiently than objects, as each key-value pair in the Map is unique.
		- Can provide better performance for large datasets or when dealing with duplicate keys.
	+ Cons:
		- May be slower due to the overhead of looking up a value in a Map (especially for very large Maps).
		- Requires more memory to store the data structure.

**Library and Purpose:**

The `Array.from()` function is used to create an array of items, where each item is an object with a key-value pair. The `Map` data structure is used to store these objects in the test case.

In this context, the `Map` library provides an efficient way to store and retrieve values using their keys. It's particularly useful when dealing with large datasets or when needing to handle collisions.

**Special JS Feature/Syntax:**

The benchmark definition uses JavaScript's `forEach()` method to iterate over the array of items and perform the access operation on both objects and Maps.

**Other Considerations:**

When writing microbenchmarks, it's essential to consider factors like:

* **Input size**: How large is the dataset being tested? Larger datasets can affect performance.
* **Data distribution**: Is the data evenly distributed across keys? Imbalanced data can skew results.
* **Browser/Platform differences**: Different browsers and platforms may have varying performance characteristics for JavaScript execution.

**Alternatives:**

If you're interested in exploring alternative approaches, here are some options:

1. **Arrays instead of Objects**: Using arrays to store values could provide different performance characteristics than using objects or Maps.
2. **Dictionaries vs. Maps**: Some languages (like Python) use dictionaries instead of Maps for key-value storage. This could affect performance and usage patterns.
3. **Other data structures**: Exploring other data structures like sets, linked lists, or trees could reveal different performance characteristics.

By considering these alternatives and factors, you can gain a deeper understanding of the complexities involved in JavaScript microbenchmarks and optimize your own code for better performance.

Related benchmarks:

map vs object - key access 3 (version: 0)

Comparing performance of: Object access vs Map get

Created: 4 years ago by: Guest

Jump to the latest result

Object access

Map get

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):