The benchmark provided compares two different methods of safely accessing nested properties within an object:

1. Optional Chaining (a feature of modern JavaScript).
2. Lodash's _.get function using a default parameter with nullish coalescing.

What is being tested

The benchmark focuses on:

• Accessing deeply nested properties in an object (obj) and handling cases where the path might not exist by providing a fallback value (2 in this case) when accessing a property that yields undefined or null.

Comparison of the two approaches

1. Optional Chaining

• Syntax: obj?.a?.b?.c?.d ?? 2

• Description:

  • The ?. operator is used to access the properties of an object without throwing an error if the property does not exist. If any part of the chain is undefined or null, the expression will return undefined, and subsequently, the ?? operator provides a fallback value (2).

• Pros:

  • Simplicity: Allows for shorter and more readable syntax.
  • Native Support: Part of the ECMAScript language, requiring no additional libraries.

• Cons:

  • Browser Support: It requires modern JavaScript support, which may not be available in all environments (though most modern browsers implement it).

2. Lodash _.get

• Syntax: _.get(obj, "a.b.c.d", 2)

• Description:

  • Lodash's _.get function safely accesses properties using a string path and accepts a default value if the property does not exist. If the specified path does not exist, it returns the provided default value.

• Pros:

  • Flexibility: Can handle a variety of use cases where dynamic property access is required.
  • Legacy Support: Works in environments where JavaScript syntax features like optional chaining may not be supported.

• Cons:

  • Dependency: Requires the Lodash library to be included, which adds to the bundle size.
  • Overhead: May have performance impacts due to function calls compared to native JavaScript syntax.

Benchmark Results

The given benchmark results show a significant performance difference:

• Optional Chaining achieved 254,689,728 executions per second.
• Lodash reached 8,923,687 executions per second.

Considerations

1. Performance: From the benchmark results, optional chaining is vastly more efficient. For scenarios where performance is critical, especially in loops or frequently executed code, optional chaining is preferable.

2. Readability: The syntax for optional chaining is generally cleaner and directly incorporates default values with nullish coalescing, useful for clarity.

3. Backward Compatibility: For large projects needing compatibility with older environments that do not support new JavaScript features, Lodash might still be a viable option for maintaining broader support.

4. Alternatives: Other potentially similar approaches include:

   • Traditional checks: Using if statements to check each property level, which can be verbose.
   • Destructuring with default values: This can also mitigate issues with undefined values, but can lead to less readable code.
   • Using TypeScript: For developers utilizing TypeScript, types can help ensure safe property access without leading to runtime errors.

In summary, the choice between optional chaining and Lodash's _.get will depend on the specific project requirements, including the target environment's JavaScript support, performance considerations, and the project's codebase maintainability.