Let's break down the benchmark and explain what's being tested.

Benchmark Definition

The benchmark is defined in two parts: Script Preparation Code and Html Preparation Code. The latter is empty, so we'll focus on the former.

The script preparation code is a piece of JavaScript that creates a new function using the new Function() constructor. This function takes a string literal as an argument and returns the result of evaluating that string as JavaScript code. In this case, the string is "return 2 * 3".

This means we have three test cases:

1. eval("2 * 3"); - uses the built-in eval() function to execute the string as JavaScript code.
2. func(); - calls a newly created function using the new Function() constructor, passing the same string literal as an argument.
3. function fff() { return 2 * 3; } - creates a new anonymous function using the function declaration syntax.

Options Compared

We're comparing three approaches:

1. eval(): executes a string as JavaScript code at runtime.
2. new Function(): creates a new function and calls it with the provided argument (in this case, the string literal).
3. Function Declaration: creates a new anonymous function using the function declaration syntax.

Pros and Cons

Here are some pros and cons of each approach:

1. eval():
   • Pros: easy to use, flexible.
   • Cons: can be a security risk if used with untrusted input, performance overhead.
2. new Function():
   • Pros: creates a new function that can be reused, avoids some security concerns of eval().
   • Cons: requires a string literal as an argument, might not be as efficient as other approaches.
3. Function Declaration:
   • Pros: explicit, readable syntax, no overhead from creating a function object.
   • Cons: not suitable for all use cases (e.g., when you need to pass arbitrary code as an argument).

Libraries and Special JS Features

There are no libraries involved in this benchmark.

Special JS Features

There is one special feature being tested:

1. Function Expressions: The new Function() constructor uses function expressions, which were introduced in ECMAScript 5 (2015). This syntax allows creating anonymous functions that can be executed later.

Alternative Approaches

Some alternative approaches to benchmarking this code might include:

• Using a more modern approach like using an Immediately Invoked Function Expression (IIFE): (function() { var func = new Function("return 2 * 3"); return func(); })()
• Measuring the performance of different JavaScript engines or versions
• Comparing the performance of eval() with other alternatives, such as Function constructor or parser.parseScript

These alternative approaches would require modifications to the benchmark code and might provide more detailed insights into the performance characteristics of each approach.