Benchmark: object map vs switch 「！！！！」

Script Preparation code:

var arr = [1, 2, 3, 4, 5]
var obj = {
    [1]: 'a',
    [2]: 'b',
    [3]: 'c',
    [4]: 'd',
    [5]: 'e'
}
var test = (val) => {
    switch (val) {
        case 1:
            return 'a';
        case 2:
            return 'b';
        case 3:
            return 'c';
        case 4:
            return 'd';
        case 5:
            return 'e';
        default:
            return '';
    }
}

Tests:

object map
const val = arr.at(Math.floor(Math.random() * 5)) const rt = obj[val]
switch
const val = arr.at(Math.floor(Math.random() * 5)) test(val)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
object map
switch

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 8 months ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_6_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.6 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 18 on iOS 18.6.2

View result in a separate tab

Test name	Executions per second
object map	99522112.0 Ops/sec
switch	99053960.0 Ops/sec

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 benchmarks.

**Benchmark Overview**

The provided JSON represents a benchmark test case for comparing the performance of two approaches: object map and switch statements. The test cases are designed to measure which approach is faster in accessing an array index from an object using the bracket notation (`[index]`).

**Object Map Approach**

In this approach, we use the `at()` method of the array to get a random index between 0 and 4 (the length of the array). We then use the bracket notation (`obj[index]`) to access the corresponding value in the object.

Pros:

* More modern and efficient way of accessing array indices from objects.
* Less verbose compared to traditional switch statements.

Cons:

* May not work as expected if the array is very large, as it uses a cached index lookup.
* Can be slower than traditional switch statements for small arrays due to the overhead of `at()` method.

**Switch Statement Approach**

In this approach, we use a traditional switch statement with multiple cases to check which value matches the random index generated by the `at()` method. If no match is found, it returns an empty string.

Pros:

* More familiar and widely supported way of accessing array indices from objects.
* Can be faster than object map for small arrays due to less overhead.

Cons:

* Less modern and less efficient way of accessing array indices from objects.
* More verbose compared to the object map approach.

**Library Used:**

There is no explicit library mentioned in the provided JSON. However, it's worth noting that the `at()` method is a part of the JavaScript Array prototype since ECMAScript 2019 (ES2020).

**Special JS Feature/Syntax:**

There are two special features used in this benchmark:

1. ** Bracket notation (`[]`)**: This syntax allows accessing an object property using its key.
2. ** Random number generation**: The `Math.floor(Math.random() * 5)` expression generates a random index between 0 and 4.

**Other Alternatives:**

If you want to explore other alternatives, here are some options:

1. **Using `in` operator instead of bracket notation**: You can use the `in` operator to access an object property using its key.
2. **Using a lookup table**: Instead of using a switch statement or bracket notation, you could create a lookup table to map each index to its corresponding value in the object.
3. **Using a library like Lodash**: If you want to simplify your code and focus on performance testing, you could use a utility library like Lodash, which provides a `get` method that can access an object property using its key.

Keep in mind that the choice of approach depends on your specific use case, performance requirements, and personal preference.

Related benchmarks:

object map vs switch 「！！！！」 (version: 0)

Comparing performance of: object map vs switch

Created: 2 years ago by: Guest

Jump to the latest result

object map

switch

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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