Benchmark Overview

The provided benchmark, angular.copy (v1.2.24) vs JSON.parse(JSON.stringify()), measures the performance difference between using the angular.copy() function and the JSON.parse(JSON.stringify()) method for copying an array of objects in JavaScript.

What is tested on the provided JSON?

The benchmark defines two test cases:

1. Angular Copy: Measures the time taken by angular.copy() to copy the original array (origArr) and store it in a new variable (newArr).
2. JSON Parse + Stringify: Measures the time taken by JSON.parse(JSON.stringify()) to copy the original array (origArr) and store it in a new variable (newArr).

Options compared

The benchmark compares two options for copying an array of objects:

• Angular Copy (angular.copy())

  • Purpose: Deep copy of arrays, which means creating a new array with copies of each element, including nested objects.
  • Pros:
    • Deep copying ensures that all references to the original elements are preserved, preventing unintended modifications to the copied data.
    • Can be used for complex data structures involving arrays and objects.
  • Cons:
    • May have performance implications due to the creation of new objects and array instances.

• JSON Parse + Stringify (JSON.parse(JSON.stringify()))

  • Purpose: Shallow copy of arrays, which means creating a new array with references to the elements of the original array.
  • Pros:
    • Faster performance compared to deep copying since no new objects are created.
    • Suitable for simple data structures involving arrays and basic JavaScript values.
  • Cons:
    • Does not preserve references to nested objects, which can lead to unintended modifications if used with complex data structures.

Other considerations

• Shallow vs Deep Copy: Both options have trade-offs. Shallow copying is faster but loses reference to nested objects, while deep copying preserves references but may be slower.
• Browser-specific differences: The benchmark results show variations between Chrome 71 on Windows and other browsers or platforms.

Library and Special JS Features

The benchmark uses the following library:

• AngularJS (angular.copy()): AngularJS is a JavaScript framework that provides various utility functions, including angular.copy() for deep copying arrays. In this case, it's used to measure performance when working with arrays containing objects.

No special JavaScript features or syntax are mentioned in the benchmark definition or execution results.

Alternatives

Other alternatives for copying arrays and objects include:

• Array.prototype.slice(): Creates a shallow copy of an array.
• Array.prototype.concat(): Combines two arrays, creating a new array with references to both original arrays.
• Lodash library functions: Offers various utility functions for manipulating data structures, including _.cloneDeep() and _assignIn().
• ES6+ features (e.g., Array.from(), Object.assign()): Provide more concise ways to create new arrays and objects.

Keep in mind that the choice of alternative depends on the specific requirements and constraints of your use case.