Benchmark: Map vs Object 2222222

Script Preparation code:

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

Tests:

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

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

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

LLMs can make mistakes. Check important info.

I'd be happy to explain what's being tested in the provided benchmark.

**Benchmark Definition**

The benchmark is defined by a JSON object that specifies two test cases:

1. `Map lookup`: This test case uses a Map data structure to store key-value pairs and performs lookups using the `.get()` method.
2. `Obj lookup`: This test case uses an object (`obj`) with a numeric property (index 0) and performs lookups using bracket notation (`obj[0]`).

**Script Preparation Code**

The preparation code sets up two variables:

* `map`: An instance of the Map data structure, initialized as an empty Map.
* `obj`: An empty object (`{}`).
* The code then inserts a key-value pair into the Map and sets a property on the object: `map.set(obj, 5)` and `obj[0] = 5`.

**Html Preparation Code**

This field is empty, indicating that no HTML preparation code is required for this benchmark.

**Test Cases**

There are two individual test cases:

1. **Map lookup**: This test case iterates 1000 times using a `for` loop, and in each iteration, it performs a lookup on the Map instance using the `.get()` method with the `obj` key.
2. **Obj lookup**: This test case also iterates 1000 times using a `for` loop, and in each iteration, it performs a lookup on the object (`obj`) using bracket notation (`obj[0]`).

**Pros and Cons**

* **Map lookup**:
	+ Pros: Maps are designed for fast lookups, and the `.get()` method is optimized for performance.
	+ Cons: If the key does not exist in the Map, it returns `undefined`, which might lead to unexpected behavior if not handled properly.
* **Obj lookup**: 
	+ Pros: Bracket notation is concise and easy to read.
	+ Cons: Object property access can be slower than Map lookups, especially when dealing with large objects.

**Library**

The `Map` data structure is a built-in JavaScript object that provides a way to store key-value pairs. Its primary purpose is to enable fast lookups by providing an efficient way to find values based on keys.

**Special JS feature**

There is no special JavaScript feature or syntax being used in this benchmark.

**Other Alternatives**

If you wanted to test these lookup operations using different data structures, you could consider the following alternatives:

* **Arrays**: Instead of Maps and objects, you could use arrays with indices. Array lookups would be faster than object lookups but might not provide the same benefits as Map lookups.
* **Set**: Sets are another data structure that provides fast lookup times, similar to Maps. They are often used for membership testing and set operations.

Keep in mind that these alternatives would require significant changes to the benchmark setup and test cases to ensure they accurately reflect the performance characteristics of each data structure.

Related benchmarks:

Map vs Object 2222222 (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):