Benchmark: Caching toLowerCase when filtering

Script Preparation code:

var data = Array(10).fill('').map(()=>String(Math.random()))
var query = '123'

Tests:

Not Cached
data.filter(it=> it.toLowerCase().includes(query.toLowerCase()))
Cached
cached = query.toLowerCase() data.filter(it=> it.toLowerCase().includes(cached))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Not Cached
Cached

Fastest: N/A

Slowest: N/A

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

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Let's break down the provided benchmark definition and test cases.

**Benchmark Definition Overview**

The benchmark measures how different approaches affect performance when filtering data in JavaScript. The script preparation code creates an array of 10 random strings, and a query string "123" is used to filter the array using the `toLowerCase()` method. The benchmark compares two approaches: one with caching (using a variable to store the cached result) and one without caching.

**Approach Comparison**

The two approaches are compared in terms of performance, measured by the number of executions per second.

1. **Not Cached**:
This approach does not cache the `toLowerCase()` result, which means that the `toLowerCase()` method is called for every iteration of the filter function.
Pros:

* No additional memory allocation or data structure overhead
Cons:

* More CPU cycles are spent on string manipulation (e.g., converting to lowercase)

2. **Cached**:
This approach caches the `toLowerCase()` result in a variable `cached`, which can be reused across iterations.
Pros:

* Reduced CPU cycles spent on string manipulation
Cons:

* Additional memory allocation for storing the cached value

Other considerations:

* The use of `includes` method instead of `indexOf` might introduce additional overhead due to its behavior (e.g., finding the first match).

**Library and Special JS Features**

There are no external libraries used in this benchmark. However, some JavaScript features are employed:

1. **Arrow functions**: Used in the `Benchmark Definition` to define small anonymous functions.
2. **Template literals**: Not explicitly used, but string concatenation is used instead (`"var query = '123'"`).

**Alternative Approaches**

Other approaches could be explored to improve performance or reduce overhead, such as:

1. **Using a `Set` data structure**:
Instead of using the `includes` method, which has a linear search complexity (O(n)), you can use a `Set` data structure to store unique lowercase strings and perform membership testing in O(1) time.
2. **Compiling or optimizing string manipulation**:
Some JavaScript engines, like V8 (used by Chrome), have compiler optimizations that reduce the overhead of string manipulation. However, this is typically a backend optimization, and may not be applicable to all scenarios.

The provided benchmark focuses on measuring performance differences between caching and non-caching approaches.

Related benchmarks:

Caching toLowerCase when filtering (version: 0)

Comparing performance of: Not Cached vs Cached

Created: 3 years ago by: Registered User

Jump to the latest result

Not Cached

Cached

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):