Benchmark: CharAt vs subscript ( [] ) in Javascript String

Script Preparation code:

const str = "Hello World";

Tests:

CharAt (0)
const str = "Hello World"; console.log(str.charAt(0))
[0]
const str = "Hello World"; console.log(str[0])
CharAt (n)
let n = 5; const str = "Hello World"; console.log(str.charAt(n))
[n]
let n = 5; const str = "Hello World"; console.log(str[n])
charAt(len-1)
const str = "Hello World"; let len = str.length; console.log(str.charAt(len-1))
[len-1]
const str = "Hello World"; let len = str.length; console.log(str[len-1])

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
CharAt (0)
[0]
CharAt (n)
[n]
charAt(len-1)
[len-1]

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/117.0.0.0 Safari/537.36

Browser/OS: Chrome 117 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
CharAt (0)	412316.9 Ops/sec
[0]	414105.2 Ops/sec
CharAt (n)	419110.2 Ops/sec
[n]	420768.9 Ops/sec
charAt(len-1)	404988.8 Ops/sec
[len-1]	419031.5 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 explain what's being tested.

**Benchmark Definition JSON**

The benchmark is defined by a single JSON object, which contains information about the test:

* `Name`: A descriptive name for the benchmark.
* `Description`: An empty string, indicating that no description was provided for this benchmark.
* `Script Preparation Code`: The JavaScript code used to prepare for each test case. In this case, it's simply a constant string `const str = "Hello World";`.
* `Html Preparation Code`: An empty string, indicating that no HTML preparation is required.

**Individual Test Cases**

The benchmark consists of six test cases, each represented by an object in the following format:

* `Benchmark Definition`: The actual JavaScript code being tested.
* `Test Name`: A descriptive name for each test case (e.g., "CharAt (n)" or "[0]").

Let's examine each test case:

1. `const str = "Hello World";\r\nconsole.log(str.charAt(0))`
	* This test case uses the `charAt` method to access the first character of the string.
2. `const str = "Hello World";\r\nconsole.log(str[0])`
	* This test case uses square brackets (`[]`) to access the first element of the string, which is equivalent to `charAt(0)`.
3. `let n = 5;\r\nconst str = "Hello World";\r\nconsole.log(str.charAt(n))`
	* This test case uses the `charAt` method with an integer index `n`, which will result in an error if `n` is out of bounds.
4. `let n = 5;\r\nconst str = "Hello World";\r\nconsole.log(str[n])`
	* Similar to the previous test case, but using square brackets (`[]`) instead of `charAt`.
5. `const str = "Hello World";\r\nlet len = str.length;\r\nconsole.log(str.charAt(len-1))`
	* This test case uses `charAt` with an index calculated from the string's length.
6. `const str = "Hello World";\r\nlet len = str.length;\r\nconsole.log(str[len-1])`
	* Similar to the previous test case, but using square brackets (`[]`) instead of `charAt`.

**Comparison**

The benchmark is comparing the performance of three different approaches:

* `charAt` method with integer indices
* Square bracket (`[]`) notation with integer indices
* `charAt` method with calculated indices from string length

**Pros and Cons:**

* `charAt` method:
	+ Pros: Provides more control over indexing, especially when working with strings.
	+ Cons: Can be slower due to the overhead of method calls.
* Square bracket (`[]`) notation:
	+ Pros: More concise and readable for simple indexing scenarios.
	+ Cons: Less flexible than `charAt`, as it doesn't support integer indices.

**Library and Special JS Features**

None of these test cases rely on any specific JavaScript libraries or special features. They are purely focused on the differences between the `charAt` method and square bracket notation.

**Alternatives**

If you're looking for alternative benchmarking tools, some popular options include:

* Google Benchmark
* benchmark.js
* microbenchmark

Each of these tools offers a range of features and options for creating custom benchmarks like this one.

Related benchmarks:

CharAt vs subscript ( [] ) in Javascript String (version: 0)

Comparing performance of: CharAt (0) vs [0] vs CharAt (n) vs [n] vs charAt(len-1) vs [len-1]

Created: 2 years ago by: Guest

Jump to the latest result

CharAt (0)

[0]

CharAt (n)

[n]

charAt(len-1)

[len-1]

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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