I'll explain the JavaScript microbenchmark being tested on MeasureThat.net.

The benchmark is designed to compare two approaches for creating TypedArray objects: using the new keyword (new Float32Array([1, 2, 3])) and using the .of() method (Float32Array.of(1, 2, 3)).

New Approach (using new)

• The new keyword is used to create a new instance of the TypedArray constructor. In this case, Float32Array.
• The callback function passed to the TypedArray constructor is used to initialize the array with values.

Pros:

1. More flexible: allows for passing options and callbacks when creating the TypedArray.
2. Compatible with older browsers that don't support .of() method.

Cons:

1. Less concise: requires more code than using .of().
2. May lead to performance issues if not implemented correctly (e.g., using new can create a temporary object that's then wrapped in the final TypedArray, which can be slower).

Of Approach (.of())

• The .of() method is used to create a new TypedArray from an array-like object or other iterable.
• In this case, it's used with an array of numbers.

Pros:

1. More concise: requires less code than using the new keyword.
2. Efficient: can be faster than using new, especially for larger arrays.

Cons:

1. Less flexible: doesn't allow for passing options or callbacks when creating the TypedArray.
2. May not work in older browsers that don't support .of() method.

Library Used

The Float32Array and TypedArray constructors are part of the Web API (ECMAScript standard), which means they're native to JavaScript.

Special JS Feature/ Syntax

There's no special JavaScript feature or syntax used in this benchmark, other than using TypedArrays, which is a modern web development concept.

Other Alternatives

If you need to create TypedArray objects in JavaScript, the .of() method is generally considered more efficient and concise. However, if you're working with older browsers that don't support .of(), or if you need more control over the creation process, using the new keyword might be a better option.

In general, for most use cases, using the .of() method is the recommended approach, as it provides better performance and conciseness.