Let's dive into the world of MeasureThat.net and explore what's being tested in this specific benchmark.

Benchmark Overview

The benchmark is designed to compare two approaches: using the spread operator (...) to add elements to an array, and using the unshift() method to add elements to the beginning of an array. The benchmark aims to determine which approach is faster and more efficient.

Options Compared

There are only two options being compared:

1. Spread Operator (...): This operator creates a new array by spreading the existing array's elements. In this case, it adds 86400 empty strings to the end of the original array.
2. Unshift() Method: This method adds one or more elements to the beginning of an array.

Pros and Cons

• Spread Operator (...):
  • Pros: Creates a new array, which can be beneficial for certain use cases (e.g., when working with large datasets).
  • Cons: Requires creating a new array, which can lead to increased memory usage.
• Unshift() Method:
  • Pros: Modifies the original array in place, reducing memory allocation and deallocation overhead.
  • Cons: Can be slower than using a spread operator for large arrays.

Library and Syntax

There is no specific library used in this benchmark. However, JavaScript's built-in Array methods are being utilized.

Special JS Feature or Syntax (Not applicable)

No special features or syntax are being tested or utilized in this benchmark.

Alternative Approaches

Other approaches that could be used to compare the performance of adding elements to an array include:

• Using the concat() method instead of the spread operator.
• Using a loop to add elements to the array (e.g., arr.push('')).
• Using a library like Lodash or Ramda, which provide additional utility functions for working with arrays.

Benchmark Preparation Code

The preparation code creates an empty array with 86400 elements and assigns it to the variable arr. This ensures that both tests are starting from the same initial state.

Individual Test Cases

Each test case has a unique benchmark definition and test name:

• The first test case uses the spread operator (arr = ['', ...arr]) and is named "spread".
• The second test case uses the unshift() method (arr.unshift('')) and is named "unshift".

Latest Benchmark Result

The latest results show that Chrome 107 on a Desktop device with Windows operating system has performed the following execution rates:

• For the "unshift" test: 34928.99609375 executions per second.
• For the "spread" test: 1396.9669189453125 executions per second.

This suggests that, in this specific scenario, using unshift() is significantly faster than using the spread operator for adding elements to an array.