Benchmark: Performance Test: substring vs substr vs slice 1

Script Preparation code:

var string = "I am the god of hellfire, and I bring you..."

Tests:

slice
var substring = string.trim().slice(0, -1);
substring
var substring = string.substring(0, string.length-1);
substr
var substring = string.substr(17, 25);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
substring
substr

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

**Benchmark Definition:**

The benchmark is designed to compare the performance of three different string manipulation methods in JavaScript:

1. `slice()`
2. `substring()`
3. `substr()`

These methods are used to extract a subset of characters from a given string.

**Options Compared:**

* `slice()`: Returns a new string containing the specified number of characters from the beginning of the original string.
* `substring()`: Returns a new string containing the specified number of characters from the beginning of the original string, starting at the specified position.
* `substr()`: Returns a new string containing the specified number of characters from the specified position in the original string.

**Pros and Cons:**

* **slice():**
	+ Pros:
		- Generally faster than `substring()` since it doesn't require specifying the length of the substring.
		- Can be used to extract a specific character or a range of characters.
	+ Cons:
		- Returns a new string, which can increase memory allocation and deallocation overhead.
		- May not work as expected if the original string is modified after calling `slice()`.
* **substring():**
	+ Pros:
		- Works well with strings that have varying lengths or are dynamically generated.
		- Can be used to extract a specific substring without creating a new string.
	+ Cons:
		- Requires specifying both the start and end indices, which can lead to errors if not done correctly.
		- May be slower than `slice()` due to the overhead of parsing the index values.
* **substr():**
	+ Pros:
		- Similar to `substring()`, but with a more traditional approach (e.g., `myString.substr(10, 5)`).
	+ Cons:
		- Less commonly used and may not be as well-supported by modern browsers or JavaScript engines.

**Library:**

There is no explicit library mentioned in the benchmark definition. However, it's worth noting that all three methods (`slice()`, `substring()`, and `substr()`) are built-in JavaScript methods that don't rely on external libraries.

**Special JS Feature/Syntax:**

There is no special JavaScript feature or syntax being tested in this benchmark. The focus is solely on comparing the performance of different string manipulation methods.

**Other Alternatives:**

If you need to extract a subset of characters from a string, other alternatives might include:

* Using regular expressions (e.g., `myString.match(/abc/gi)`).
* Employing string concatenation and slicing (e.g., `"abc".slice(0, 3) + "def"`).
* Utilizing the `split()` method with an empty separator string (e.g., `"abc".split("")`).

Keep in mind that these alternatives may have different performance characteristics or use cases compared to the methods being tested in this benchmark.

Related benchmarks:

Performance Test: substring vs substr vs slice 1 (version: 0)

Comparing performance of: slice vs substring vs substr

Created: 3 years ago by: Guest

Jump to the latest result

slice

substring

substr

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):