Benchmark: push vs assign - MeasureThat.net

Tests:

push
const list1 = []; for (var i = 0; i < 1000 * 1000; i++) { list1.push(i); }
assign
const list2 = new Array(1000); for (var i = 0; i < 1000 * 1000; i++) { list2[i] = i; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
push
assign

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

**Understanding the Benchmark**

The provided JSON represents a JavaScript microbenchmark that compares two approaches to add elements to an array: using the `push()` method or the assignment operator (`=`) directly on the array.

**Options Compared**

Two options are compared:

1. **`push()`**: This method appends one or more elements to the end of an array and returns the length of the resulting array.
2. **Assignment Operator (`=`)**: This operator creates a new array by assigning a value to each element of the original array.

**Pros and Cons**

* **`push()`**:
	+ Pros: Efficient in terms of memory allocation, as it modifies the existing array without creating a new one.
	+ Cons: May be slower than assignment due to function call overhead.
* **Assignment Operator (`=`)**:
	+ Pros: Can be faster for large arrays, as it avoids the overhead of the `push()` method and creates a new array in a single step.
	+ Cons: Consumes more memory, creating a new array with the same elements.

**Library Used**

In this benchmark, no external library is used. The code snippets provided are self-contained JavaScript functions that perform the specified operations on arrays.

**Special JS Feature or Syntax**

The benchmark uses **`for...of` loops**, which were introduced in ECMAScript 2015 (ES6). This loop syntax provides a more concise and expressive way to iterate over arrays, but it's not available in older browsers. The benchmark assumes that the test environment supports ES6 features.

**Other Considerations**

When choosing between `push()` and assignment, consider the following:

* **Memory allocation**: If memory is a concern, using `push()` might be more efficient.
* **Performance**: For large arrays, assignment might be faster due to reduced function call overhead.
* **Code readability**: Using assignment can make code easier to read, as it clearly expresses the intention of creating a new array.

**Alternatives**

Other alternatives for adding elements to an array include:

* **`splice()` method**: This method replaces or inserts elements at a specified position in the array. While more versatile than `push()`, it can be slower and consumes more memory.
* **`concat()` method**: This method creates a new array by concatenating two or more arrays. It's similar to assignment but can be less efficient for large arrays.

In summary, the benchmark compares two approaches to add elements to an array: using the `push()` method versus the assignment operator. Each approach has its pros and cons, and the choice depends on the specific use case, performance requirements, and code readability considerations.

Related benchmarks:

push vs assign (version: 0)

Comparing performance of: push vs assign

Created: 3 years ago by: Guest

Jump to the latest result

push

assign

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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