Benchmark Explanation

The provided JSON represents a JavaScript microbenchmark test case on the MeasureThat.net website. The benchmark compares the execution performance of three different approaches to access object values:

1. _.values(a): This approach uses the Lodash library's values function to retrieve the object values.
2. Object.values(a): This is a built-in JavaScript method that returns an array containing the property values of the specified object.
3. proposal-object-values-entries/polyfill.js: This is a polyfill for the proposed Object.valuess and Object.entries methods, which are not yet supported in all browsers.

Options Compared

The benchmark compares the execution performance of these three approaches on different JavaScript engines. The options being compared are:

• _.values(a): Uses Lodash's values function.
• Object.values(a): Built-in JavaScript method for accessing object values.
• proposal-object-values-entries/polyfill.js: Polyfill for proposed Object.valuess and Object.entries methods.

Pros and Cons of Different Approaches

1. _.values(a):
   • Pros:
     • Widely supported by Lodash and other libraries.
     • Easy to use and understand.
   • Cons:
     • May introduce additional dependencies (Lodash).
     • Might be slower due to the added overhead of a library function call.
2. Object.values(a):
   • Pros:
     • Built-in JavaScript method, eliminating dependency on external libraries.
     • Can be faster since it's a native method with optimized implementation.
   • Cons:
     • Not yet supported in older browsers or environments without recent updates.
3. proposal-object-values-entries/polyfill.js:
   • Pros:
     • Provides a unified way to access object values across different browsers and engines.
     • Can be useful for projects targeting older browsers or environments.
   • Cons:
     • May introduce additional dependencies (polyfills).
     • Might be slower due to the added overhead of a polyfill.

Library - Lodash

Lodash is a popular JavaScript library that provides a set of high-order functions and utility methods. The values function in this benchmark is used to retrieve an array of values from an object. Lodash's values function leverages the Object.values method, which was introduced in ECMAScript 2017.

Special JS Feature - Spread Operator (Rest Parameter)

The spread operator (...) is a syntax feature introduced in ECMAScript 2015. It allows for creating new arrays or objects by spreading existing ones. In this benchmark, the Function.bind.call(Function.call, Array.prototype.reduce) syntax uses a rest parameter to handle variable numbers of arguments. This is not related to the main comparison but demonstrates advanced JavaScript features.

Alternatives

Other alternatives for accessing object values include:

• Object.keys(a): Returns an array of keys (property names) in the specified object.
• for...in: Iterates over the properties of an object using a for loop.
• Array.prototype.forEach(): Iterates over the property values of an object using a callback function.

These alternatives might be useful depending on the specific use case, but they may not offer the same performance benefits as native methods like Object.values(a).