Benchmark: Js Search - String StartsWith vs IndexOf vs Includes

Tests:

Starts With
var a = '![](file:///Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua'; var b = a.startsWith('![](file:///');
Index Of
var a = '![](file:///Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua'; var b = a.indexOf('![](file:///');
Includes
var a = '![](file:///Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua'; var b = a.includes('![](file:///');

Historical Performance Data aggregated from 12 community runs

Desktop Results:

Chrome 12 runs

Index Of

168.7M/s

Includes

164.4M/s

Starts With

55.4M/s

Fastest: Index Of (3.0x faster)

View exact numbers

✓ Index Of: 168,674,880 ops/sec
• Includes: 164,446,176 ops/sec
• Starts With: 55,373,688 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Starts With
Index Of
Includes

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/605.1.15 (KHTML, like Gecko) Version/18.4 Safari/605.1.15

Browser/OS: Safari 18 on Mac OS X 10.15.7

View result in a separate tab

Index Of

538.9M/s

Starts With

81.9M/s

Includes

51.0M/s

View exact numbers

Test name	Executions per second
✓ Index Of	538,896,192 Ops/sec
Starts With	81,869,360 Ops/sec
Includes	51,012,824 Ops/sec

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

LLMs can make mistakes. Check important info.

**Overview**

The provided benchmark measures the performance of three string search methods in JavaScript: `startsWith`, `indexOf`, and `includes`. These methods are commonly used to check if a substring is present within a larger string.

**Benchmark Definition**

The JSON data defines two test cases:

1. "Starts With"
2. "Index Of"
3. "Includes"

Each test case involves creating a string (`a`) with a sample Lorem ipsum text and then checking if another string (`b`) starts with, contains as an index, or includes the specified substring.

**Options Compared**

The benchmark compares three different string search methods:

1. **`startsWith`**: Returns `true` if the string `b` starts with the specified substring.
2. **`indexOf`**: Returns the index of the first occurrence of the specified substring in the string `a`. If the substring is not found, returns `-1`.
3. **`includes`**: Returns `true` if the string `a` includes the specified substring.

**Pros and Cons**

*   **`startsWith`**:
    *   Pros: More efficient than `indexOf` or `includes`, especially when searching for a specific prefix.
    *   Cons: May not be as intuitive to use, as it requires careful consideration of edge cases (e.g., empty strings).
*   **`indexOf`**:
    *   Pros: Simple to use and understand, with minimal overhead. Suitable for most use cases where the search is not exact.
    *   Cons: Can be slower than `startsWith`, especially when searching for a specific prefix or substring in a large string.
*   **`includes`**:
    *   Pros: More readable and intuitive than `indexOf`, with fewer edge cases to consider. Suitable for most use cases where the search is exact.
    *   Cons: May be slower than `startsWith` due to the overhead of searching for the substring in the entire string.

**Library Usage**

None of the benchmark test cases explicitly use a JavaScript library. However, it's worth noting that some libraries (e.g., Lodash) provide optimized implementations of these methods.

**Special JS Features or Syntax**

There are no special JavaScript features or syntax used in this benchmark.

**Other Alternatives**

Other string search methods in JavaScript include:

*   `localeCompare`: Compares two strings based on their locale and language settings.
*   `match`: Returns an array of matches for a regular expression applied to the string.
*   `replace`: Replaces occurrences of a specified pattern in the string with a new value.

Keep in mind that each of these methods has its own strengths, weaknesses, and use cases. This benchmark provides a concise way to compare the performance of three common string search methods: `startsWith`, `indexOf`, and `includes`.

If you're interested in exploring other options or learning more about the trade-offs between these methods, I can provide additional resources or guidance!

Js Search - String StartsWith vs IndexOf vs Includes (version: 0)

Comparing performance of: `Starts With vs Index Of vs Includes`

Created: 4 years ago by: Guest

Go to the latest result

Starts With

Index Of

Includes

Historical Performance Data aggregated from 12 community runs

Desktop Results:

Chrome 12 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Js Search - String StartsWith vs IndexOf vs Includes (version: 0)

Comparing performance of: Starts With vs Index Of vs Includes

Created: 4 years ago by: Guest

Go to the latest result

Starts With

Index Of

Includes

Historical Performance Data aggregated from 12 community runs

Desktop Results:

Chrome 12 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

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Comparing performance of: `Starts With vs Index Of vs Includes`