Benchmark: Reference vs New Variable

Tests:

Reference
const myArray = [{id: 1}, {id: 1}, {id: 1}, {id: 1}, {id: 1}, {id: 1}, {id: 1}, {id: 1}, {id: 1}]; function addingFunction(number) { return number + 1; } function myFunction(arr) { let myValue; myArray.forEach((a) => { myValue = () => addingFunction(a.id); }); } myFunction(myArray);
New Variable
const myArray = [{id: 1}, {id: 1}, {id: 1}, {id: 1}, {id: 1}, {id: 1}, {id: 1}, {id: 1}, {id: 1}]; function addingFunction(number) { return number + 1; } function myFunction(arr) { let myValue; myArray.forEach((a) => { const b = () => addingFunction(a.id); myValue = b; }); } myFunction(myArray);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Reference
New Variable

Fastest: N/A

Slowest: N/A

Latest run results:

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Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark definition and test cases to understand what is being tested.

**Benchmark Definition:**

The website uses a simple benchmark that compares the cost of two approaches:

1. **Reference**: In this approach, a new variable `b` is declared inside the loop and then assigned to `myValue`. This creates a reference to the function object `b`, which points to the same function as `myValue`.
2. **New Variable**: In this approach, a new variable `b` is declared inside the loop and then immediately assigned to `myValue`. However, instead of creating a reference to the function object `b`, the assignment creates a copy of the function.

**What are we testing?**

We're testing which approach has a lower overhead in terms of performance. The idea behind this test is that the Reference approach should be faster because it reuses the same function object, whereas the New Variable approach creates a new function object on each iteration.

**Pros and Cons:**

* **Reference Approach:**
	+ Pros:
		- Reuses the same function object, which can lead to better performance.
		- Less overhead due to fewer function creations.
	+ Cons:
		- May cause issues if the function is modified externally after creation.
		- Can be less intuitive for developers who are not familiar with this approach.
* **New Variable Approach:**
	+ Pros:
		- Creates a new scope, which can help prevent naming conflicts.
		- More intuitive for developers who prefer a more explicit assignment syntax.
	+ Cons:
		- Creates a new function object on each iteration, which can lead to higher overhead.

**Library and Special JS Features:**

There are no libraries used in this benchmark. However, it does utilize the `let` keyword with the Destructuring Assignment feature (introduced in ECMAScript 2015) to create a new variable inside the loop.

The `const myValue;` line declares a constant variable `myValue`, and the destructuring assignment `(a) => addingFunction(a.id)` is used to destructure the value of `a` into a function expression. This syntax allows us to write concise code that is easier to read and maintain.

**Other Alternatives:**

If you're interested in exploring alternative approaches, here are a few options:

1. **Use an arrow function**: You can replace the `myFunction(arr)` implementation with an arrow function, which would eliminate the need for the explicit `b` variable.
```javascript
arr.forEach((a) => myValue = () => addingFunction(a.id));
```
2. **Use a closure**: Instead of creating a new variable inside the loop, you can create a closure by returning a new function from the `myFunction` implementation.
```javascript
function myFunction(arr) {
  let myValue;
  return arr.forEach((a) => (myValue = () => addingFunction(a.id)));
}
```
Keep in mind that these alternatives may have different performance characteristics and trade-offs, so it's essential to test them thoroughly.

Overall, the Reference approach is likely to be faster due to its lower overhead, but the New Variable approach has its own advantages. It's essential to consider the specific requirements of your use case when choosing an approach.

Related benchmarks:

Reference vs New Variable (version: 0)

This looks at the cost of assigning a new

Comparing performance of: Reference vs New Variable

Created: 7 years ago by: Guest

Jump to the latest result

Reference

New Variable

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):