Benchmark: Diff empty array

Tests:

with if-check
let updates = [5, 23, 42] const removedItems = [] if (removedItems.length) { updates = updates.filter((id) => !removedItems.includes(id)); }
without if-check
const removedItems = [] const updates = [5, 23, 42].filter((id) => !removedItems.includes(id));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
with if-check
without if-check

Fastest: N/A

Slowest: N/A

Latest run results:

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

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I'll break down the benchmark and explain what's being tested, compared, and what pros and cons come with each approach.

**Benchmark Purpose**

The primary goal of this benchmark is to measure the performance difference in removing items from an array using two different methods: with an `if` check and without it. The focus is on comparing the execution speed of these two approaches.

**Script Preparation Code**

There is no script preparation code provided, which means that the JavaScript engine will start executing the benchmark scripts from scratch for each test run. This approach can help isolate the test results from any external factors that might influence the outcome, such as caching or previous function calls.

**Comparison of Approaches**

The two approaches being compared are:

1. **With `if` check**: The code uses an `if` statement to check if `removedItems` has length before filtering the `updates` array.
```javascript
if (removedItems.length) {
  updates = updates.filter((id) => !removedItems.includes(id));
}
```
Pros:

* Can be useful in certain situations where the condition might not always be true, reducing unnecessary computations.

Cons:

* Introduces additional overhead due to the conditional statement evaluation.
* May lead to slightly slower execution times compared to the `without if-check` approach.

2. **Without `if` check**: The code uses a simple array filter method without any condition.
```javascript
const updates = [5, 23, 42].filter((id) => !removedItems.includes(id));
```
Pros:

* Eliminates the overhead of the conditional statement evaluation.
* Typically results in faster execution times.

Cons:

* May lead to performance degradation if the condition is not met, as the filter method will still be executed and produce an empty array.

**Library Usage**

The `filter()` method is a built-in JavaScript function that iterates over an array and applies a callback function to each element. The purpose of this function is to create a new array with only the elements that pass the test implemented by the provided function.

**Special JS Feature/Syntax**

There are no special JavaScript features or syntax used in these benchmark scripts. They use standard JavaScript syntax and built-in functions.

**Other Alternatives**

Some alternative approaches for removing items from an array include:

* Using `slice()` method: `const updates = [5, 23, 42].slice(removedItems.length);`
* Using `reduce()` method: `const updates = [5, 23, 42].reduce((acc, id) => {
  if (!removedItems.includes(id)) acc.push(id);
  return acc;
}, []);`

Keep in mind that these alternative approaches may have different performance characteristics and might not be suitable for all use cases.

In the context of this benchmark, the `filter()` method is likely to be the most efficient approach, as it provides a concise and expressive way to filter arrays. However, if the condition is known to be false for certain elements, using `slice()` or `reduce()` might lead to slightly slower execution times.

Related benchmarks:

Diff empty array (version: 0)

Comparing performance of: with if-check vs without if-check

Created: 5 years ago by: Registered User

Jump to the latest result

with if-check

without if-check

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):