The provided benchmark tests performance differences between using a plain JavaScript object ({}) and a JavaScript Map in terms of deletion operations. Below is an explanation of what is being tested, the approaches involved, their pros and cons, along with consideration of libraries and alternative solutions.

Benchmark Overview

Objective: The benchmark aims to compare the deletion performance of elements from two data structures: a standard JavaScript object and a Map.

Test Cases

1. Object Deletion:

   for (let i1 = 0; i1 < 10000; i1++) {
     delete d1[i1];
   }
   

   • Test Name: Creation: Object
   • Functionality: This loop deletes properties from a plain JavaScript object d1.

2. Map Deletion:

   for (let i2 = 0; i2 < 10000; i2++) {
     d2.delete(i2);
   }
   

   • Test Name: Creation: Map
   • Functionality: This loop deletes entries from a Map object d2.

Results Interpretation

The benchmark results indicate that the deletion operation from the Map is significantly faster than from the plain JavaScript object. The following execution speeds were recorded:

• Map Deletion: 20,753 executions per second
• Object Deletion: 3,371 executions per second

Pros and Cons

Plain Object ({}):

• Pros:

  • Simplicity: Using a plain object is straightforward and familiar for many developers.
  • Lower memory overhead for small numbers of properties.

• Cons:

  • Slower performance on deletion operations, especially when the number of properties increases.
  • Not suitable for non-string keys (e.g., objects or functions).
  • Inherits properties from Object.prototype, potentially causing issues with property name collisions unless checked.

Map:

• Pros:

  • Faster performance on addition and deletion due to optimized internal mechanisms.
  • Supports any data type as keys (not just strings).
  • Maintains the order of elements, which can be beneficial in certain use cases.

• Cons:

  • Slightly more memory overhead than plain objects for small sets of data.
  • More complexity in operations if the data structure is relatively simple.

Other Considerations

• Use Cases: When you need a simple key-value storage without high performance needs, objects are sufficient. However, if you require frequent additions and deletions, or need to use non-string keys, Map is the better choice.

• Alternatives: Other alternatives include:

  • Sets: For storing unique values without duplicates, although they do not directly offer key-value pairs like objects or maps.
  • WeakMap: Similar to Map, but entries can be garbage collected if there are no other references to the keys, useful for memory management.
  • Libraries: While this benchmark doesn’t test external libraries, libraries like Immutable.js or Lodash can provide structures that may optimize performance for specific use cases, particularly immutable data handling.

Conclusion

This benchmark effectively illustrates the performance differences in deletion between JavaScript objects and maps. It highlights the scenarios in which each structure can be most effective and guides developers in selecting the right data structure for optimal performance depending on their specific use cases.