Benchmark: slice vs substring (with no end index)

Script Preparation code:

var example = 'there is no spoon.'

Tests:

slice
var result = example.slice(0, -1)
substring
var result = example.substring(0, example.lastIndexOf("."))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
substring

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 10 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:140.0) Gecko/20100101 Firefox/140.0

Browser/OS: Firefox 140 on Windows

View result in a separate tab

Test name	Executions per second
slice	296679136.0 Ops/sec
substring	97040160.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data and explain what's being tested, compared, and the pros and cons of each approach.

**Benchmark Definition**

The benchmark is comparing three JavaScript methods: `slice()`, `substr()`, and `substring()` when only a start index is provided. The goal is to determine which method performs better in this scenario.

**Options Compared**

1. **Slice()**: Returns a new string containing all characters from the original string, starting at the specified index, up to but not including the specified end index (exclusive).
2. **Substr()**: Returns a substring of the original string, starting at the specified index, with the specified length.
3. **Substring()**: Returns a substring of the original string, starting at the specified start index, for the specified length.

**Pros and Cons**

* **Slice()**:
	+ Pros: Fast and efficient, as it only creates a new array of indices to iterate over.
	+ Cons: Can be slower than `substr()` or `substring()` if the end index is close to the start index.
* **Substr()**: 
	+ Pros: Can be faster than `slice()` or `substring()` when dealing with large strings, as it only needs to copy a substring of the original string.
	+ Cons: Not supported in older browsers, and can lead to security issues if not used carefully (e.g., using untrusted input).
* **Substring()**: 
	+ Pros: Slightly more readable than `substr()` for some users, especially when working with non-integer start or end indices.
	+ Cons: Can be slower than `slice()` due to the overhead of parsing the substring.

**Library and Syntax**

There are no libraries being used in this benchmark. The focus is on native JavaScript methods only.

**Special JS Features/Syntax**

None, but it's worth noting that the benchmark does use a special string literal (`"there is no spoon."`), which may be optimized by some browsers or engines.

**Alternative Approaches**

Other approaches could involve:

1. **String.prototype.includes()**: A more modern and efficient method for finding substrings.
2. **RegEx**: Regular expressions can also be used to find substrings, but may have different performance characteristics due to the regex engine's overhead.
3. ** Native methods from a specific library (e.g., jQuery) or framework**: Depending on the context, other libraries or frameworks might provide optimized string manipulation methods.

Overall, this benchmark provides a clear and concise comparison of three essential JavaScript string methods, allowing users to determine which approach performs best in common use cases.

Related benchmarks:

slice vs substring (with no end index) (version: 0)

Compares slice, substr and substring to each other when there is only a start index

Comparing performance of: slice vs substring

Created: 4 years ago by: Guest

Jump to the latest result

slice

substring

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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