Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

Benchmark Overview

The provided benchmark tests three different approaches to find an element in two arrays: indexOf, concat, and a more modern approach using the spread operator (...). The benchmark aims to determine which method is the most efficient.

Script Preparation Code

The script preparation code initializes two arrays, aaa and bbb, with some sample values. It also sets up a variable term to be searched for in both arrays.

var aaa = [1,2,3];
var bbb = [2,3,4];
var term = 1;

Html Preparation Code

There is no HTML preparation code provided, which means that the benchmark focuses solely on the JavaScript implementation.

Test Cases

The test cases are defined in the following JSON array:

[
    {
        "Benchmark Definition": "aaa.indexOf(term) > -1 || bbb.indexOf(term) > -1",
        "Test Name": "separate"
    },
    {
        "Benchmark Definition": "aaa.concat(bbb).indexOf(term) > -1",
        "Test Name": "concat"
    },
    {
        "Benchmark Definition": "[...aaa, ...bbb].indexOf(term) > -1",
        "Test Name": "cool concat"
    }
]

Each test case defines a different benchmarking scenario:

• separate: Directly calls indexOf on both arrays individually and checks if the term exists in either of them.
• concat: Concatenates the two arrays using the spread operator (...) and then calls indexOf on the resulting array to find the term.
• cool concat: Similar to concat, but uses the spread operator (...) to concatenate the arrays. This approach is more modern and efficient.

Library Used

None of the test cases use any external libraries, which means that the results are specific to vanilla JavaScript implementation.

Special JS Feature or Syntax

The benchmark does not specifically target any special JavaScript features or syntax. However, it does demonstrate a modern approach using the spread operator (...), which is a standard feature in modern JavaScript implementations.

Pros and Cons of Each Approach

Here's a brief analysis of each approach:

• separate: This method is straightforward but may lead to slower performance due to the need to search for the term in both arrays individually.
• concat: Concatenating the arrays using the spread operator can be efficient, as it allows the browser to optimize the array creation process. However, this approach may incur additional overhead due to the temporary array creation.
• cool concat: This modern approach using the spread operator is likely to be the most efficient, as it avoids creating a temporary array and directly searches for the term in the concatenated array.

Other Alternatives

Some alternative approaches that could have been tested include:

• Using find instead of indexOf, which may provide better performance due to early termination.
• Using a more advanced data structure like a Set or a Trie, which may provide faster lookup times.
• Using SIMD instructions (if supported by the browser) to perform multiple comparisons simultaneously.

However, these alternatives are not explored in the provided benchmark.