I'd be happy to help you understand the JavaScript microbenchmark on MeasureThat.net.

Benchmark Overview

The benchmark compares the performance of two approaches: using _.forEach() from the Lodash library and using a traditional for loop (also known as a "native" loop). The goal is to measure which approach is faster for iterating over an array of objects.

Lodash _.forEach() Approach

• Library: Lodash is a popular JavaScript utility library that provides various functions for tasks such as array manipulation, string manipulation, and more.
• Purpose: In this benchmark, Lodash's _.forEach() function is used to iterate over the values array. The callback function passed to _.forEach() increments a counter (count) whenever it encounters an object with a non-null value on the a property.

Native Approach

• Traditional Loop: This approach uses a traditional for loop to iterate over the values array. Inside the loop, the code checks if each object has a non-null value on the a property and increments a counter (count) if true.
• Pros:
  • More control over iteration logic
  • Generally faster than using a library function like Lodash's _.forEach()
• Cons:
  • More verbose code compared to using a library function
  • Requires manual memory management for array access

Special JavaScript Features/Syntax

None mentioned in the provided benchmark.

Other Alternatives

Besides the two approaches shown, other alternatives could be:

• Using Array.prototype.forEach(): This is another built-in method for iterating over an array. While similar to Lodash's _.forEach() function, it might have different performance characteristics due to its implementation.
• Using a for loop with an index variable: Similar to the native approach, this would involve manually incrementing an index variable and checking the value of each object on the array.

Benchmark Results

The latest benchmark results show that:

• The "native" approach outperforms the Lodash _.forEach() function, with a higher number of executions per second.
• Chrome 76 performs slightly better than any other browser, indicating platform-specific optimizations or performance characteristics.

Keep in mind that these results might vary depending on the specific test environment and system configuration.