Benchmark: startsWith vs includes('something', 0)

Tests:

includes
const str = "https://firebase.com/this/is/a/long/thing" str.includes("https://firebase", 0)
startsWith
const str = "https://firebase.com/this/is/a/long/thing" str.startsWith("https://firebase")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
includes
startsWith

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases to understand what's being tested.

**Benchmark Definition JSON**

The benchmark definition is a simple JavaScript expression that compares two string methods: `startsWith` and `includes`. The script preparation code and HTML preparation code are empty, which means no additional setup or rendering of HTML is required for this benchmark.

**Test Cases**

There are only two test cases:

1. **`includes`**: This test case measures the performance of the `includes()` method with a substring starting from index 0.
2. **`startsWith`**: This test case measures the performance of the `startsWith()` method.

**String Methods Comparison**

The comparison between `startsWith` and `includes` is based on their implementation differences:

*   `startsWith()`: Returns `true` if the string starts with the specified value, otherwise returns `false`. It does a simple byte-by-byte comparison.
*   `includes(index: number): boolean`: Returns `true` if the string contains the specified value at the specified index, otherwise returns `false`.

**Pros and Cons of Different Approaches**

1.  **Byte-by-Byte Comparison (startsWith)**:
    *   Pros: Simple to implement and highly optimized for performance.
    *   Cons: May be slower due to direct comparisons.

2.  **Substring Search (includes)**:
    *   Pros: Often faster than byte-by-byte comparison due to optimized internal algorithms, but still may have a higher overhead compared to `startsWith`.
    *   Cons: More complex implementation and potentially slower.

**Library Usage**

None of the test cases use any libraries.

**Special JS Features or Syntax**

The benchmark does not specifically use any special JavaScript features or syntax that would affect its outcome. The results should be representative of typical browser behavior.

**Other Alternatives**

For measuring string method performance, other alternatives might include:

1.  **V8 Benchmark Suite**: A set of benchmarks developed by Google to measure the performance of the V8 JavaScript engine.
2.  **JavaScript Performance Comparison Tool (JSC)**: Another tool for comparing the performance of JavaScript engines.

**Benchmark Preparation Code**

The provided script preparation code and HTML preparation code are empty, indicating that no additional setup or rendering is required for this benchmark. This allows users to directly run their own tests with a minimalistic configuration.

Related benchmarks:

startsWith vs includes('something', 0) (version: 0)

Comparing performance of: includes vs startsWith

Created: 2 years ago by: Guest

Jump to the latest result

includes

startsWith

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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