I'll break down the benchmark and its options, pros and cons, and considerations.

Benchmark Overview

The benchmark compares two ways of concatenating strings in JavaScript: template strings (also known as template literals) and String.concat() (version 2).

Template Strings vs. String.concat v2

Template strings are a feature introduced in ECMAScript 2015 (ES6). They allow you to embed expressions inside string literals, using the $ symbol followed by an expression.

In this benchmark, the template string version uses the ${} syntax to concatenate three values: base, separator, and suffix.

The String.concat() version, on the other hand, uses the concat() method with two arguments, which concatenates the first argument with the second argument.

Pros and Cons

Template Strings:

Pros:

1. Readability: Template strings are more readable, as they clearly show the intent of concatenating values.
2. Performance: Some benchmarks have shown that template strings can be faster than String.concat() due to the compiler's ability to optimize them at compile-time.

Cons:

1. Compatibility: Older browsers and Node.js versions may not support template strings or may have limited support.
2. Complexity: When using multiple values, template strings can become complex and harder to read.

String Concat v2:

Pros:

1. Wide compatibility: String.concat() has been part of JavaScript since its inception and is widely supported across browsers and Node.js versions.
2. Simple syntax: The syntax is straightforward and easy to understand.

Cons:

1. Readability: Using concat() can make the code harder to read, as it requires more manual effort to concatenate values.
2. Performance: Some benchmarks have shown that String.concat() can be slower than template strings due to the overhead of function calls and string concatenation.

Other Considerations

When choosing between these two options, consider the following:

1. Performance: If you need high-performance string concatenation, template strings might be a better choice.
2. Readability: If readability is more important than performance, template strings are likely a better option.
3. Compatibility: If you need to support older browsers or Node.js versions, String.concat() might be a safer choice.

Library and Special JS Features

There are no libraries used in this benchmark. However, the use of template strings demonstrates the newer ECMAScript 2015 (ES6) feature.

Alternatives

If you're looking for alternative ways to concatenate strings, consider:

1. String.prototype.join(): This method concatenates multiple values into a single string.
2. Array.prototype.concat(): This method concatenates two arrays together.

Note that these alternatives may have different performance characteristics and readability trade-offs compared to template strings or String.concat().

Benchmark Preparation Code

The provided script preparation code defines the base, separator, and suffix variables, as well as the two functions: templateString() and stringConcat(). The templateString() function uses a template string, while the stringConcat() function uses concat().

The benchmark is designed to run these two functions repeatedly, measuring their performance and comparing the results.