Benchmark: Performance Test: substring vs substr vs slice vs split

Script Preparation code:

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

Tests:

slice
var substring = string.slice(17, 25);
substring
var substring = string.substring(17, 25);
substr
var substring = string.substr(17, 25);
split
var substring = string.split(',')[1];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
substring
substr
split

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36

Browser/OS: Chrome 146 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
slice	180157120.0 Ops/sec
substring	161157232.0 Ops/sec
substr	173935008.0 Ops/sec
split	43169012.0 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.

**Benchmark Definition**

The benchmark is designed to compare the performance of four string manipulation methods:

1. `substring()`
2. `substr()`
3. `slice()`
4. `split()` (specifically, splitting a comma-separated string)

**Options Compared**

Each test case compares two options for creating a substring or split string.

*   For `substring()`, the comparison is between `string.substring(17, 25)` and `string.slice(17, 25)`.
*   For `substr()`, the comparison is between `string.substr(17, 25)` and `string.slice(17, 25)`.
*   For `split()`, the comparison is between `string.split(',')[1]` and no alternative (i.e., just using `string` as a single value).

**Pros and Cons of Different Approaches**

Here's a brief overview of each approach:

*   **`substring()`**: This method returns a new string containing a section of the original string. It's generally considered the most readable and maintainable option among the four.
    *   Pros: Easy to read, clear purpose, efficient for small substrings.
    *   Cons: Can be slower than other methods for large substrings.
*   **`substr()`**: This method is similar to `substring()`, but it's less commonly used in modern JavaScript. It returns a new string containing a section of the original string, starting from the offset specified by the second argument.
    *   Pros: Similar to `substring()`, but can be slightly faster due to its native implementation.
    *   Cons: Less readable and maintainable than `substring()`, less commonly used in modern JavaScript.
*   **`slice()`**: This method returns a new array containing a section of the original string. When used with two arguments, it returns an array containing one element (a substring). It's generally faster than `substring()` for large substrings.
    *   Pros: Fast, efficient for large substrings, flexible in its usage (can be used as an array or string).
    *   Cons: Less readable and maintainable than `substring()`, can be confusing when used with arrays.
*   **`split()`**: This method splits a string into an array of substrings based on a specified separator. When using only one argument, it returns the entire string if it doesn't contain the separator.
    *   Pros: Fast and efficient for splitting strings.
    *   Cons: Not suitable for extracting substrings from a single string.

**Library**

The `split()` method uses the built-in JavaScript `String.prototype.split()` method. This method is implemented in native code, making it fast and efficient.

**Special JS Feature/Syntax**

There are no special features or syntaxes used in this benchmark that would require additional explanation.

**Other Considerations**

When choosing between these string manipulation methods, consider the following factors:

*   **Readability**: Choose `substring()` for its clear purpose and readability.
*   **Performance**: Use `slice()` for large substrings due to its native implementation and efficiency.
*   **Flexibility**: Consider using `split()` when working with comma-separated strings or arrays.

**Alternatives**

Some alternative string manipulation methods you might consider include:

*   **Regular expressions (RegExp)**: Useful for complex pattern matching, but can be slower than the other methods for simple substring extraction.
*   **Array methods**: Such as `slice()`, `substr()`, and `indexOf()`, which can be useful when working with arrays or strings in a more functional programming style.

Related benchmarks:

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

Comparing performance of: slice vs substring vs substr vs split

Created: 5 years ago by: Guest

Jump to the latest result

slice

substring

substr

split

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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