Benchmark: speedtest - MeasureThat.net

Script Preparation code:

var field = 'fieldname[]';

Tests:

substring
field.substring(field.length - 2);
slice
field.slice(0,-2)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
substring
slice

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in the provided JSON benchmark.

**Benchmark Definition**

The benchmark definition is a JavaScript expression that is executed to measure its performance. In this case, there are two test cases:

1. `field.substring(field.length - 2)`
2. `field.slice(0,-2)`

Both expressions aim to extract a substring from the `field` variable.

**Options compared**

The benchmark compares the performance of two different string slicing approaches:

* `substring`: The `substring()` method extracts a section of a string and returns it.
* `slice`: The `slice()` method also extracts a section of a string, but it takes an optional start index and end index to define the slice.

**Pros and Cons**

Here's a brief summary of each approach:

1. **`substring()`**:
	* Pros: Simple and straightforward. It only requires the length of the substring.
	* Cons: May not be as efficient as `slice()` because it creates an intermediate result object.
2. **`slice()`**:
	* Pros: More flexible, allowing for optional start and end indices.
	* Cons: Requires specifying both start and end indices, which might lead to errors if not done correctly.

In general, `slice()` is considered faster than `substring()`, especially when dealing with large strings or strings that are close to the edge (i.e., `length - 1`).

**Library usage**

There is no explicit library mentioned in the benchmark definition. However, it's worth noting that `slice()` is a built-in method of JavaScript arrays and strings.

**Special JS feature or syntax**

There is an example of using square bracket notation `[ ]`, which is used to access array elements. In this case, the code uses `field[]` (implied by the JSON representation) to access the `field` variable as an array.

**Other alternatives**

If you wanted to compare performance with other string slicing approaches, you could consider using:

1. **`substr()`**: Similar to `substring()`, but it returns a string value instead of creating an intermediate result object.
2. **`String.prototype.slice()`**: A shorthand version of the `slice()` method that takes only two arguments: the start index and the end index.

Keep in mind that performance differences between these methods might be negligible unless you're dealing with extremely large strings or performance-critical code.

Overall, the benchmark is designed to compare the performance of `substring()` and `slice()` when extracting a substring from an array or string.

Related benchmarks:

speedtest (version: 0)

Comparing performance of: substring vs slice

Created: 4 years ago by: Guest

Jump to the latest result

substring

slice

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):