Benchmark: .endsWith vs last char check

Script Preparation code:

var string = 'x';
var stringToCheck = 'alksjdflaksjdlkajtlkadjsta;ksdglkasdjfadsfaf';
var intIndexLast = stringToCheck.length - 1

var result = null;

Tests:

.endsWith
result = stringToCheck.endsWith(string);
last index
result = stringToCheck[ intIndexLast ] === string;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
.endsWith
last index

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/104.0.0.0 Safari/537.36

Browser/OS: Chrome 104 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
.endsWith	5013728.5 Ops/sec
last index	3993574.8 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what is being tested, compared options, their pros and cons, and other considerations.

**Benchmark Definition**

The benchmark is designed to compare two approaches for checking if a string ends with another string: `.endsWith()` method versus accessing the last character of the string directly (`string[intIndexLast] === string`).

**Script Preparation Code**

The script preparation code defines two variables:

* `string`: a simple string literal `'x'`.
* `stringToCheck`: a more complex string literal `'alksjdflaksjdlkajtlkadjsta;ksdglkasdjfadsfaf'`.

**Html Preparation Code**

There is no HTML preparation code provided.

**Individual Test Cases**

There are two test cases:

1. `.endsWith()`
2. `last index`

**Library Used**

The benchmark does not explicitly mention a specific library, but it uses the `.endsWith()` method, which is a built-in JavaScript method for checking if a string ends with another string.

**Special JS Feature/Syntax**

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

**Options Compared**

Two options are compared:

1. `.endsWith()`: This method checks if the end of the string matches the given string.
2. `last index`: This approach accesses the last character of the string directly using indexing (`string[intIndexLast]`) and then compares it with the other string.

**Pros and Cons**

Here's a brief overview of the pros and cons of each approach:

1. `.endsWith()`:
	* Pros:
		+ Concise and readable code
		+ Efficient, as it only needs to check a portion of the string
	* Cons:
		+ May be slower for very large strings due to the method call overhead
2. `last index`:
	* Pros:
		+ Can be faster for very large strings, as it avoids the method call overhead
	* Cons:
		+ Requires careful indexing and handling of edge cases (e.g., null or undefined string)

**Other Considerations**

When choosing between these two approaches, consider the following:

* For most use cases, `.endsWith()` is a good choice due to its conciseness and readability.
* If performance is critical for very large strings, `last index` might be a better option. However, this approach requires careful handling of edge cases.

**Alternatives**

Other alternatives for checking if a string ends with another string include:

1. Using the `lastIndexOf()` method with `-1` to get the length of the string.
2. Using a regular expression (e.g., `new RegExp('^.+$')`) to match the end of the string.

These alternatives may offer different trade-offs in terms of conciseness, performance, and readability, depending on the specific use case.

Related benchmarks:

.endsWith vs last char check (version: 0)

Comparing performance of: .endsWith vs last index

Created: 2 years ago by: Guest

Jump to the latest result

.endsWith

last index

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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