Benchmark: Mapping (Key vs Index)

Script Preparation code:

let a = {};
for (let i = 0; i < 1000; i++) {
    a[`cond-${i}`] = [];
    for (let y = 0; y < 1000; y++) {
        a[`cond-${i}`].push(y);
    }
}

let b1 = [];
let b2 = [];
for (let i = 0; i < 1000; i++) {
    b1[i] = [];
    b2.push(`cond-${i}`);
    for (let y = 0; y < 1000; y++) {
        b1[i].push(y);
    }
}


function lookup_a(id) {
  return a[id];
}

function lookup_b(id) {
  return b1[b2.indexOf(id)];
}

Tests:

Lookup (Key based)
for (let i = 0; i < 1000; i++) { lookup_a(`cond-${i}`) }
Lookup (Index based)
for (let i = 0; i < 1000; i++) { lookup_b(`cond-${i}`) }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Lookup (Key based)
Lookup (Index based)

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's break down the benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is designed to compare the performance of two approaches: looking up a value in an object using its key (also known as "key-based") versus looking up a value in an array using its index (also known as "index-based").

**Script Preparation Code**

The script preparation code creates two objects, `a` and `b`, and populates them with arrays. The object `a` has 1000 properties, each containing an array of 1000 values. The array `b1` is initialized with 1000 empty arrays, while the array `b2` contains strings representing the property names in `a`.

**Functions**

Two functions are defined:

* `lookup_a(id)`: takes a string as input and returns the corresponding value from object `a`.
* `lookup_b(id)`: takes a string as input and returns the corresponding value from array `b1` using the index provided by the string in `b2`.

**Test Cases**

There are two test cases:

* **Lookup (Key based)**: This test case calls `lookup_a(`cond-${i}`)` 1000 times, where `i` ranges from 0 to 999.
* **Lookup (Index based)**: This test case calls `lookup_b(`cond-${i}`)` 1000 times, where `i` ranges from 0 to 999.

**Options Compared**

The benchmark is comparing the performance of two approaches:

1. **Key-based**: Looking up a value in an object using its key (using `lookup_a(id)`).
2. **Index-based**: Looking up a value in an array using its index (using `lookup_b(id)`).

**Pros and Cons of Each Approach**

* **Key-based**:
	+ Pros: More readable and intuitive, easier to maintain.
	+ Cons: Can be slower than index-based lookup due to the overhead of string manipulation and object lookups.
* **Index-based**:
	+ Pros: Can be faster than key-based lookup, especially for large arrays.
	+ Cons: Less readable and more prone to errors, especially when dealing with complex array indices.

**Library Used**

In this benchmark, no specific library is used. The script only uses built-in JavaScript features and functions.

**Special JS Feature or Syntax**

This benchmark does not use any special JavaScript features or syntax beyond the standard features mentioned above.

**Alternative Approaches**

Other approaches to compare in this benchmark might include:

* Using a hash table (e.g., `Map`) instead of an object for key-based lookup.
* Using a binary search tree (BST) instead of an array for index-based lookup.
* Using a different data structure, such as a linked list or a queue, for both key-based and index-based lookups.

Note that the choice of approach depends on the specific use case and requirements.

Related benchmarks:

Mapping (Key vs Index) (version: 0)

Comparing performance of: Lookup (Key based) vs Lookup (Index based)

Created: 3 years ago by: Guest

Jump to the latest result

Lookup (Key based)

Lookup (Index based)

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):