Benchmark: slice vs substr vs substring to truncate string

Script Preparation code:

var example = 'there is no spoon'

Tests:

slice
var result = example.slice(0,10)
substr
var result = example.substr(0,10)
substring
var result = example.substring(0,10)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
substr
substring

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/133.0.0.0 Safari/537.36

Browser/OS: Chrome 133 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
slice	166101792.0 Ops/sec
substr	171870928.0 Ops/sec
substring	92257944.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

LLMs can make mistakes. Check important info.

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

**What is being tested?**

The benchmark is designed to compare three different string manipulation methods in JavaScript: `slice()`, `substr()`, and `substring()`. The test case uses a fixed string `example = 'there is no spoon'`.

**Options compared**

*   **Slice**: `var result = example.slice(0,10)`
    *   This method creates a new string object containing the characters of `example` from index 0 up to (but not including) index 10.
    *   The pros: efficient for large strings, returns a new string without modifying the original, and has fewer dependencies compared to substr and substring methods.
    *   The cons: requires two parameters: start index and length. If not provided, slice throws an error if it is called with zero arguments.
*   **Substr**: `var result = example.substr(0,10)`
    *   This method extracts a section of a string. It returns the characters of `example` starting at index 0 up to (but not including) index 10.
    *   The pros: less parameters compared to slice and substring methods, it's faster than slice in practice because of how browsers are optimized to handle substr calls.
    *   The cons: this method is slower than the slice method in most cases due to browser optimizations.
*   **Substring**: `var result = example.substring(0,10)`
    *   This method creates a new string object containing the characters of `example` from index 0 up to (but not including) index 10.
    *   The pros: similar to slice in terms of efficiency and has fewer dependencies compared to substr. It's actually faster than substr because it is called less often.
    *   The cons: requires two parameters, similar to the slice method, but with a different name.

**Other considerations**

*   **Library:** None
*   **Special JS feature or syntax**: None

The benchmark provides results for the three methods:

| Test Name | Browser          | DevicePlatform  | OperatingSystem        | ExecutionsPerSecond |
| --- | --- | --- | --- | --- |
| slice   | Chrome 108         | Desktop        | Linux                 | 5242033.0            |
| substr  | Chrome 108         | Desktop        | Linux                 | 5233290.0            |
| substring | Chrome 108        | Desktop       | Linux                | 4146559.75           |

**Pros and Cons of Each Approach:**

1.  **Slice**
    *   Pros:
        *   More efficient for large strings.
        *   Returns a new string without modifying the original string.
        *   Fewer dependencies compared to substr and substring methods.
    *   Cons:
        *   Requires two parameters (start index and length).
2.  **Substr**
    *   Pros:
        *   Less parameters compared to slice and substring methods.
        *   Faster than slice in practice because of browser optimizations.
    *   Cons:
        *   Slower than the slice method in most cases due to browser optimizations.
3.  **Substring**
    *   Pros:
        *   Similar to slice in terms of efficiency.
        *   Fewer dependencies compared to substr.
        *   Faster than substr because it is called less often.

**Alternatives**

*   Other string manipulation methods like `indexOf()`, `lastIndexOf()`, or regular expressions (`RegExp`) are not being tested.
*   There are other libraries like Lodash, which may offer more efficient implementations for these functions.

Related benchmarks:

slice vs substr vs substring to truncate string (version: 0)

Compares slice, substr and substring to each other when the start index is 0

Comparing performance of: slice vs substr vs substring

Created: 4 years ago by: Registered User

Jump to the latest result

slice

substr

substring

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):