Benchmark Overview

MeasureThat.net is a platform for comparing the performance of different JavaScript approaches to manipulate arrays. The provided benchmark defines four test cases: Control (for push), Concat, Spread, and Flat. These tests measure how fast each approach can append elements to an array.

Test Cases and Approaches

1. Control (for push):
   • Approach: Using the push() method, which appends one or more elements to the end of an array.
   • Example Benchmark Definition: window.top.tests.control = window.arrays.reduce((acc, arr) => {\r\n acc.push(...arr);\r\n return acc;\r\n}, []);
2. Concat:
   • Approach: Using the concat() method, which returns a new array that is the result of concatenating an array with another array or value.
   • Example Benchmark Definition: window.top.tests.concat = window.arrays.reduce((acc, arr) => acc.concat(arr), []);
3. Spread:
   • Approach: Using the spread operator (...) to expand an array into its individual elements and then reassigning them to a new array.
   • Example Benchmark Definition: window.top.tests.spread = window.arrays.reduce((acc, arr) => [...acc, ...arr], []);
4. Flat:
   • Approach: Using the flat() method, which returns an array with all sub-array elements concatenated into it recursively up to a specified depth.
   • Example Benchmark Definition: window.top.tests.flat = window.arrays.flat();

Pros and Cons

Each approach has its strengths and weaknesses:

• Control (for push):
  • Pros: Simple and efficient, as it only requires pushing elements onto the array.
  • Cons: Can be slower for large arrays due to the overhead of repeatedly calling push().
• Concat:
  • Pros: Creates a new array, which can avoid modifying the original array.
  • Cons: Requires creating an intermediate array and copying its contents, which can be slow for large arrays.
• Spread:
  • Pros: Avoids modifying the original array and uses the spread operator, which is efficient.
  • Cons: Can be slower than push() due to the overhead of expanding the array using the spread operator.
• Flat:
  • Pros: Recursively flattens the array, avoiding the need for explicit looping or concatenation.
  • Cons: Can be slower due to the recursive nature of flat().

Library and Special JS Features

The benchmark uses the following libraries:

• No external libraries are used in this benchmark.
• The reduce() method is used, which is a built-in JavaScript array method that applies a function to each element in an array.

No special JS features are mentioned in the benchmark definition.