Benchmark: Last char remove V1.0

Script Preparation code:

var x = "slice vs substring - remove last char";

Tests:

Slice
x.slice(10);
Substring
x.substring(0, x.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: 4 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.2 Safari/605.1.15

Browser/OS: Safari 26 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Slice	324767680.0 Ops/sec
Substring	323665568.0 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 benchmark and its options.

**Benchmark Purpose:**
The benchmark measures the performance difference between two string manipulation methods in JavaScript: `slice()` and `substring()`. Specifically, it tests how long each method takes to remove the last character from a given string.

**Options Compared:**

1. **`slice()`**: The `slice()` method returns a new string that contains all characters of the original string except for the last one. It is often used when you need to extract a subset of characters from a larger string.
2. **`substring()`**: The `substring()` method returns a new string that contains all characters of the original string, starting from a specified index and ending at a specified end index (exclusive). When only an end index is provided, it effectively removes the last character.

**Pros and Cons:**

*   **`slice()`**:
    *   Pros:
        +   More straightforward to use when you need to extract a subset of characters.
        +   Can be more efficient for large strings since it returns a new string without modifying the original.
    *   Cons:
        +   Creates an additional object in memory, which can impact performance if used extensively.
*   **`substring()`**:
    +   Pros:
        +   Modifies the original string, making it potentially faster than `slice()`.
        +   Can be more efficient for strings that are already being modified elsewhere.
    *   Cons:
        +   Can return unexpected results when used incorrectly (e.g., if the end index is less than 0).
        +   May not be suitable for all use cases where you need to preserve the original string.

**Library:**
There are no libraries explicitly mentioned in the provided benchmark definition or test case. However, it's worth noting that JavaScript engines like V8 (used by Chrome) and SpiderMonkey (used by Firefox) implement these string manipulation methods. The performance differences between `slice()` and `substring()` can be influenced by how well the engine optimizes these methods.

**Special JS Feature/Syntax:**
There are no special features or syntax mentioned in this benchmark that require any particular knowledge of JavaScript beyond its basic functionality.

**Alternatives:**

*   Other string manipulation methods like `indexOf()`, `lastIndexOf()`, `charAt()`, and `substr()` could be compared to see which ones offer the best performance for specific use cases.
*   The benchmark also doesn't account for potential differences in performance when using these methods on different types of strings (e.g., arrays, regex patterns).
*   For more advanced JavaScript features or syntax, consider benchmarks like the popular "JSPerf" or "BenchmarkJS" tests.

Related benchmarks:

Last char remove V1.0 (version: 0)

Comparing performance of: Slice vs Substring

Created: 3 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):