Benchmark: Map vs Object (2)

Script Preparation code:

var map = new Map();
var obj = {};

var i = 0,
    count = 100000,
    a;

function getKey(i) {
    return `i-${i}`;
}

for (i = 0; i < count; i++) {
    var key = getKey(i);
    var value = {
        i,
        key
    };
    map.set(key, value);
    obj[key] = value;
}

Tests:

Map lookup
for (i = 0; i < count; i++) { a = map.get(getKey(i)); }
Obj lookup
for (i = 0; i < count; i++) { a = obj[getKey(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 break down the benchmark and its test cases.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmark that compares the performance of two data structures: Maps and objects (specifically, JavaScript Objects). The benchmark is defined by creating a map and an object with the same key-value pairs and then performing lookups on both data structures to retrieve values.

**Options Compared**

Two options are being compared:

1. **Map Lookup**: This option uses the `map.get()` method to retrieve values from the map.
2. **Object Lookup**: This option uses the `[key]` syntax to retrieve values from the object.

**Pros and Cons of Each Approach**

* **Map Lookup**
	+ Pros:
		- Map lookups are generally faster than object lookups because maps use a hash table implementation, which provides constant-time performance.
		- Maps can handle large amounts of data without significant performance degradation.
	+ Cons:
		- Map lookups require the browser to iterate through the map's entries, which can be slower for small datasets.
* **Object Lookup**
	+ Pros:
		- Object lookups are often faster than map lookups for small datasets because they only require a single property access.
		- Objects can be more convenient to use for simple key-value pairs.
	+ Cons:
		- Object lookups can be slower than map lookups as the dataset grows, especially if the object is large and deeply nested.

**Library/Feature Used**

* **Map**: The `Map` data structure is a built-in JavaScript data structure that allows for fast lookup, insertion, and deletion of key-value pairs. It's implemented as an object with its own set of methods (e.g., `get()`, `set()`, etc.).

**Special JS Feature/Syntax**

* **Template Literals**: The `getKey()` function uses template literals to create dynamic keys. Template literals are a feature introduced in ECMAScript 2015 that allows you to embed expressions inside string literals.

**Other Alternatives**

If you wanted to modify this benchmark, here are some alternative approaches:

* Compare using other data structures like arrays or sets.
* Use different lookup methods, such as `indexOf()` for objects or `indexOf()` for arrays.
* Increase the dataset size to observe the impact on performance.
* Use a more complex key-value pair structure (e.g., nested objects) to see how it affects performance.

Overall, this benchmark is useful for understanding the trade-offs between using maps and objects in JavaScript applications, particularly when dealing with large datasets.

Related benchmarks:

Map vs Object (2) (version: 0)

Lookup of map vs object

Comparing performance of: Map lookup vs Obj lookup

Created: 3 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):