Benchmark: create array - MeasureThat.net

Tests:

new array with length
var a = new Array(10); for (var i = 0; i<10; i++) { a[i] = i; }
new array with push
var a = []; for (var i = 0; i<10; i++) { a.push(i); }
new array with length 2
var a = Array(10); for (var i = 0; i<10; i++) { a[i] = i; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
new array with length
new array with push
new array with length 2

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 the performance of JavaScript microbenchmarks is crucial to understand how different browsers, devices, and operating systems handle various use cases.

**Benchmark Definition:**
The provided benchmark definition represents a basic script that creates an array using three different methods:

1. `var a = new Array(10);`: This method uses the `new` keyword to create an array with a specified length.
2. `var a = []`; : This method uses the empty array literal syntax (`[]`) to create an empty array, which is then populated with values using the `push()` method.
3. `var a = Array(10);`: This method uses the `Array` constructor to create an array with a specified length.

The script prepares for each test case by creating an empty string (`""`) and then discarding it using the `document.write()` method, which is not used in this specific benchmark but is included in other tests.

**Options Compared:**
In this benchmark, we're comparing three different approaches to create an array:

1. **`new` keyword**: This approach uses the `new` keyword to create an array with a specified length.
2. **Empty array literal syntax (`[]`)**: This approach uses the empty array literal syntax to create an empty array, which is then populated with values using the `push()` method.
3. **`Array` constructor**: This approach uses the `Array` constructor to create an array with a specified length.

**Pros and Cons of Each Approach:**

1. **`new` keyword**:
	* Pros: Efficient, as it directly creates an array object without the need for additional syntax or methods.
	* Cons: May not work in older browsers that don't support the `Array()` constructor.
2. **Empty array literal syntax (`[]`)**:
	* Pros: Works in most modern browsers and is a concise way to create an empty array.
	* Cons: Requires additional steps to populate the array, which may incur performance overhead.
3. **`Array` constructor**:
	* Pros: Allows for more flexibility in creating arrays with different lengths or types of elements.
	* Cons: May be slower than the `new` keyword approach and is less efficient than using the empty array literal syntax.

**Library Usage:**
There are no libraries used in this benchmark, as it only involves basic JavaScript syntax and data structures.

**Special JS Features or Syntax:**
This benchmark doesn't use any special JavaScript features or syntax. However, some test cases might require knowledge of:

* Array methods like `push()`, `length`, or `concat()`
* Object creation and manipulation

**Alternative Approaches:**
Other approaches to create arrays in JavaScript include:

1. Using the `Array.prototype.slice()` method to create a new array from an existing one.
2. Utilizing the `Map` data structure instead of arrays, which provides more efficient lookups and updates.
3. Leveraging libraries like Lodash or Ramda for array operations.

Keep in mind that the choice of approach depends on the specific use case, performance requirements, and compatibility considerations.

Latest run results:

Run details: (Test run date: 7 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.116 Safari/537.36

Browser/OS: Chrome 53 on Linux

View result in a separate tab

Test name	Executions per second
new array with length	1903098.2 Ops/sec
new array with push	5855753.5 Ops/sec
new array with length 2	2362303.2 Ops/sec

Related benchmarks:

create array (version: 0)

Comparing performance of: new array with length vs new array with push vs new array with length 2

Created: 7 years ago by: Guest

Jump to the latest result

new array with length

new array with push

new array with length 2

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):