Benchmark: slice vs substring (start-end)

Script Preparation code:

var example = 'there is no spoon'

Tests:

slice
var result = example.slice(1, - 1)
substring
var result = example.substring(1, example.length - 1)

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: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/132.0.0.0 Safari/537.36 Edg/132.0.0.0

Browser/OS: Chrome 132 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
slice	193139648.0 Ops/sec
substring	187413888.0 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):

LLMs can make mistakes. Check important info.

The benchmark in question compares three string manipulation methods in JavaScript: `slice`, `substring`, and `substr`. However, the provided test cases focus on the first two methods (`slice` and `substring`), while `substr` is mentioned but not included in the benchmarks shown.

### Options Compared
1. **slice**
   - **Definition**: `example.slice(start, end)` extracts a section of a string based on the provided start and end indices.
   - **Usage in Benchmark**: `var result = example.slice(1, -1);`
     - This extracts the substring starting from index 1 up to (but not including) the last index (due to the negative index indicating to start counting from the end).

2. **substring**
   - **Definition**: `example.substring(start, end)` also extracts a section of a string but treats negative indices differently; it will treat them as zero.
   - **Usage in Benchmark**: `var result = example.substring(1, example.length - 1);`
     - This extracts the substring from index 1 to the second-to-last character.

### Pros and Cons

**slice**
- **Pros**:
  - Supports negative indices, which are useful for quickly referencing parts of a string from the end.
  - Considered more flexible overall due to its indexing capabilities.
  
- **Cons**:
  - Users unfamiliar with the negative index behavior may unintentionally produce unexpected results.

**substring**
- **Pros**:
  - Simple and straightforward handling of indices, making it easy to understand for basic use.
  - Does not consider negative indices, which some might find less confusing.

- **Cons**:
  - Lack of support for negative indices can lead to more verbose code when needing to access the end of a string.
  - Less flexible in terms of the parameters accepted.

### Other Considerations

- **Performance**: Based on the benchmark results collected from a specific browser and operating system setup, `slice` performed slightly better than `substring` with execution rates of approximately 193 million and 187 million operations per second, respectively. These results could vary significantly across different environments and implementations, so they should be taken as indicative rather than absolute.
  
- **Compatibility**: Both methods are well-supported across all modern browsers, so developers generally do not need to worry about compatibility when using them.

### Alternatives

1. **substr**: This method is similar to `slice` and `substring` but extracts a substring starting from a specified index for a given number of characters. However, it is considered a legacy feature in JavaScript, and its use is discouraged in favor of `slice` or `substring`.

- **Usage Example**: `var result = example.substr(1, 4);` would extract 4 characters starting from index 1.

2. **String Methods Use**: Depending on the requirements, developers may also consider using other string manipulation methods such as `split` (to divide a string into an array) or template literals for more advanced operations and construction of strings.

3. **Regular Expressions**: For more complex string patterns and manipulation, regular expressions (Regex) may also be viable alternatives, allowing for sophisticated searches and replacements within strings.

In summary, while `slice` and `substring` are both valid approaches for substring extraction, `slice` may be more advantageous in scenarios requiring flexible index manipulation due to its support for negative indices. Understanding these method differences allows software engineers to choose the most appropriate option for their use cases.

Related benchmarks:

slice vs substring (start-end) (version: 1)

Compares slice, substr and substring to each other

Comparing performance of: slice vs substring

Created: one year 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 gpt-4o-mini, generated one year ago):