This benchmark tests the performance of two different approaches to creating a new array that excludes one element from an existing array in JavaScript:

1. slice() and splice():

• This method uses two built-in functions:
  • slice(): Creates a shallow copy of a portion of an array without modifying the original.
  • splice(): Modifies the original array by removing elements at a specific index range.

The code snippet array.slice().splice(38, 1) first creates a copy of the array using slice() and then uses splice() to remove one element from that copy (at index 38).

2. ES6 Array Spread Syntax:

• This method leverages the concise syntax introduced in ECMAScript 6. The spread operator (...) allows you to expand an array into its individual elements within a new array literal.

The code snippet [...array].splice(38, 1) first uses the spread operator to create a new array containing all the elements of the original array, and then modifies that new array using splice() to remove one element (at index 38).

Pros & Cons:

• slice() & splice():

  • Cons: More verbose, potentially less readable. Requires understanding how both functions work together.
  • Pros: Works in older JavaScript versions that don't support ES6 syntax.

• ES6 Array Spread Syntax:

  • Cons: Requires knowledge of ES6 features, may not be supported in all browsers.
  • Pros: More concise and readable, potentially more efficient due to a single array operation.

Other Considerations:

• splice() vs. slice(): The choice between these two methods depends on whether you need to modify the original array or simply create a new one without changes.
• Alternatives:
  • For simpler cases, filtering can be used with filter() method:

    const newArray = array.filter((val, i) => i !== 38);
    

Test Results:

In this specific benchmark, the ES6 Array Spread Syntax slightly outperforms the traditional slice() & splice() approach. This result is consistent with the generally expected performance advantage of using modern JavaScript features like spread syntax.