Benchmark: temptest - MeasureThat.net

Tests:

array
String.prototype.replaceAt = function(index, char) { var a = this.split(""); a[index] = char; return a.join(""); }; 'abcde'.replaceAt(2,'a')
const array
String.prototype.replaceAt = function(index, char) { const a = this.split(""); a[index] = char; return a.join(""); }; 'abcde'.replaceAt(2,'a')
...array
String.prototype.replaceAt = function(index, char) { var a = [...this]; a[index] = char; return a.join(""); }; 'abcde'.replaceAt(2,'a')
const ...array
String.prototype.replaceAt = function(index, char) { const a = [...this]; a[index] = char; return a.join(""); }; 'abcde'.replaceAt(2,'a')
assign
String.prototype.replaceAt = function(index, char) { return Object.assign([...this], {[index]: char}).join(``); }; 'abcde'.replaceAt(2,'a')

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array
const array
...array
const ...array
assign

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Measuring JavaScript performance!

The provided JSON represents the benchmark definition and test cases for measuring the performance of different approaches to replacing characters in a string using the `replaceAt` method on the `String.prototype`.

**Benchmark Definition:**

The benchmark definition is not explicitly defined, but it can be inferred from the script preparation code. The script attempts to redefine the `replaceAt` method on the `String.prototype`, which is used to replace a character at a specified index.

**Options Compared:**

The following options are compared in the test cases:

1. **Using `this.split('')`**: This approach creates an array of characters by splitting the string into individual characters.
2. **Using `const a = this`**: This approach uses a constant variable to create a copy of the original string.
3. **Using array destructuring (`...this`)**: This approach uses array destructuring to create a new array with the specified character.
4. **Using `Object.assign()`**: This approach uses the `Object.assign()` method to merge two objects (in this case, an array and an object with the replacement character).

**Pros and Cons of Each Approach:**

1. **Using `this.split('')`**:
	* Pros: simple and straightforward.
	* Cons: creates a new array, which can lead to memory allocation overhead.
2. **Using `const a = this`**:
	* Pros: more efficient than the first approach, as it doesn't create a new array.
	* Cons: uses a constant variable, which can be less readable.
3. **Using array destructuring (`...this`)**:
	* Pros: creates a new array with the specified character, without modifying the original string.
	* Cons: only supported in modern browsers and Node.js environments ( ECMAScript 2015+).
4. **Using `Object.assign()`**:
	* Pros: efficient and easy to read.
	* Cons: requires creating an object with the replacement character, which can lead to additional memory allocation.

**Other Considerations:**

* **Library usage:** None of the test cases use any external libraries or frameworks.
* **Special JS features or syntax:** The only special feature used is array destructuring (`...this`), which is a modern JavaScript feature. This may affect the compatibility of the benchmark across different environments.
* **Alternative approaches:** Other approaches to replacing characters in a string, such as using `replace()` method with a regular expression, are not tested.

**Benchmark Results:**

The provided benchmark results show the performance of each approach on various devices and browsers. The results suggest that:

* Using `this.split('')` is relatively slow.
* Using `const a = this` is faster than the first approach but slower than the other two options.
* Using array destructuring (`...this`) is significantly faster than the first approach and comparable to using `Object.assign()`.
* Using `Object.assign()` is the fastest option, especially for large strings.

Overall, the benchmark results suggest that using `Object.assign()` or array destructuring (`...this`) are good approaches to replacing characters in a string on modern browsers and Node.js environments.

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36

Browser/OS: Chrome 81 on Windows 7

View result in a separate tab

Test name	Executions per second
array	761719.6 Ops/sec
const array	676513.4 Ops/sec
...array	533901.6 Ops/sec
const ...array	516282.8 Ops/sec
assign	206667.5 Ops/sec

Related benchmarks:

temptest (version: 0)

temp

Comparing performance of: array vs const array vs ...array vs const ...array vs assign

Created: 4 years ago by: Guest

Jump to the latest result

array

const array

...array

const ...array

assign

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):