In this benchmark, three approaches to defining and invoking functions in JavaScript are compared based on their performance when calculating the power of a number (using the exponentiation operator **). Each test utilizes a different method to define and invoke a function:

Test Cases Compared

1. Function Declaration (Method): o.f1(123, 345)

   • Definition: f1(a, b) { a ** b }
   • Type: Traditional function declaration.
   • Execution: This method directly calls a defined method on an object.

2. Arrow Function: o.f2(123, 345)

   • Definition: f2: (a, b) => { return a ** b }
   • Type: Concise syntax for functions introduced in ES6 (ECMAScript 2015).
   • Execution: Utilizes the arrow function syntax with an explicit return value. It is bound to the enclosing scope, bringing a different handling of the this context.

3. Optional Chaining with Undefined: o.f3?.(123, 345)

   • Definition: f3: undefined (no actual function).
   • Type: Syntax used to safely access properties or call methods on potentially undefined or null values.
   • Execution: The optional chaining operator (?.) allows the test to safely attempt to invoke f3 without throwing an error even though f3 is explicitly set to undefined.

Performance Results

Executions Per Second:

• f1: 250,836,128.0
• f3: 244,662,144.0
• f2: 227,694,608.0

Analysis of Pros and Cons

1. Function Declaration (f1):

   • Pros:
     • The traditional method is straightforward and easy to understand.
     • It benefits from performance optimizations in JavaScript engines for named functions.
   • Cons:
     • Slightly less flexible than arrow functions in terms of this binding.

2. Arrow Function (f2):

   • Pros:
     • More concise and modern syntax; often leads to cleaner code.
     • Lexically binds this, which can be beneficial in certain contexts (like callbacks in methods).
   • Cons:
     • In some JavaScript environments or for certain use cases, there may be a slight performance overhead due to the need for context binding.

3. Optional Chaining (f3):

   • Pros:
     • Safeguards against TypeError when attempting to call methods on undefined or null.
     • Useful in scenarios where a method may or may not exist.
   • Cons:
     • Since f3 is undefined, it offers no performance benefits and serves as a redundancy in this benchmark context.
     • The performance will not reflect actual function execution since there is no valid workload.

Considerations and Alternatives

• The test highlights differences in function invocation methods that can impact performance. While using the ** operator is straightforward, the distinctions in how functions are defined and executed can lead to performance variations depending on the JavaScript engine optimizations.
• Alternatives include:
  • Using standard function expressions instead of arrow functions.
  • Using built-in methods (like Math.pow) for some calculations, which can also be benchmarked to see how they perform in comparison to custom implementations.
  • Including more complex calculations or workloads in benchmarks could provide deeper insights, as performance may vary with input sizes or algorithmic complexity.

This benchmark provides valuable insights into function invocation performance in JavaScript, revealing that traditional functions may still have an edge in execution speed compared to newer syntax, though the practical differences may be negligible for many use-cases.