Benchmark: .startsWith() vs .test() vs .match() vs .indexOf() and equals

Script Preparation code:

var html = "https://";

Tests:

regexp .test()
/^https?:\/\//.test(html)
string .match()
!!html.match(/^https:\/\//)
indexOf === 0
html.indexOf('http://') === 0
string .startsWith()
html.startsWith('https://')
equals
html === 'https://'

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
regexp .test()
string .match()
indexOf === 0
string .startsWith()
equals

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down the test cases and explain what's being tested.

**Benchmark Definition**

The benchmark is comparing four string comparison methods:

1. `.startsWith()`
2. `.test()`
3. `.match()`
4. `indexOf()` with equality check (`=== 0`)
5. Direct equality check (`==`)

These methods are being compared to test their performance, accuracy, and consistency.

**Test Cases**

Each test case is a small script that exercises one of the comparison methods on a specific input string. Here's what each test case does:

1. `regexp .test()`: Verifies if the input string matches the regular expression `/^https?:\/\//`.
2. `string .match()`: Verifies if the input string contains the substring `/http:/` (case-insensitive).
3. `indexOf === 0`: Verifies if the first character of the input string is `h`.
4. `string .startsWith()`: Verifies if the input string starts with `https://`.
5. `equals`: Directly checks if the input string equals `"https://"`.

**Libraries and Special JS Features**

None of these test cases use a specific library, but they do utilize built-in JavaScript features:

* Regular expressions (`.test()` and `.match()`)
* String methods (`startsWith()`, `indexOf()`, and `equals`)

No special JavaScript features are being tested in this benchmark.

**Pros and Cons**

Here's a brief summary of the pros and cons of each comparison method:

1. `.startsWith()`: Fast and efficient, but may not work as expected for strings with multiple leading characters (e.g., `"https://www."`).
2. `.test()` and `.match()`: More flexible than `startsWith()`, but may be slower due to the overhead of regular expression parsing.
3. `indexOf === 0`: Simple and fast, but only checks the first character; may not work for longer strings or more complex comparisons.
4. Direct equality check (`==`): Fast and simple, but can lead to issues with type coercion (e.g., `"https "` !== `"https"`).

**Alternatives**

Other alternatives to these comparison methods include:

* Using `String.prototype.localeCompare()` for case-insensitive comparisons
* Utilizing a library like Lodash's `isEqual()` function for more complex equality checks
* Employing string manipulation techniques, such as using `replace()` or `trim()`, to normalize input strings before comparison

Overall, the benchmark is testing the performance and accuracy of different string comparison methods in JavaScript.

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/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36

Browser/OS: Chrome 119 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
regexp .test()	11302570.0 Ops/sec
string .match()	9916723.0 Ops/sec
indexOf === 0	17635466.0 Ops/sec
string .startsWith()	11596054.0 Ops/sec
equals	18201072.0 Ops/sec

Related benchmarks:

.startsWith() vs .test() vs .match() vs .indexOf() and equals (version: 0)

Comparing performance of: regexp .test() vs string .match() vs indexOf === 0 vs string .startsWith() vs equals

Created: one year ago by: Guest

Jump to the latest result

regexp .test()

string .match()

indexOf === 0

string .startsWith()

equals

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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