Benchmark: Object.assign template vs direct assignment

Script Preparation code:

var array = [];
const ii = 10000;
for (let i = 0; i < ii; ++i) {
    const data = {};
    data.a = i;
    data.b = 'y';
    data.c = false;
    array.push(data);
}

Tests:

Direct Assignment
array.forEach((data,index) => { data.x = index + 1; data.y = 'a'; data.z = true; });
Object.assign template
let template = {x:0, y:'a',z:true}; array.forEach((data,index) => { template.x = index + 1; Object.assign(data, template); });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Direct Assignment
Object.assign template

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's break down the benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark compares two approaches for assigning values to objects within an array: direct assignment using `forEach` with arrow functions, and using `Object.assign` with a template object.

**Approaches Compared**

There are two main approaches:

1. **Direct Assignment**: The code uses the `forEach` method with an arrow function to iterate over the array. Within the callback function, it directly assigns values to the `data` object.
2. **Object.assign Template**: This approach uses the `Object.assign` method to merge a template object (`template`) into each `data` object in the array.

**Pros and Cons of Each Approach**

1. **Direct Assignment**
	* Pros:
		+ Simple and concise code
		+ No extra memory allocation or copying required (since it's assigning directly)
	* Cons:
		+ May be slower due to the overhead of iterating over the array using `forEach`
		+ Can lead to unexpected behavior if not careful with variable scope and naming
2. **Object.assign Template**
	* Pros:
		+ More readable and maintainable code, as it explicitly defines the template values
		+ Can be faster, since `Object.assign` is optimized for performance
	* Cons:
		+ Requires an extra step to define the template object
		+ May lead to unnecessary memory allocation or copying if not used carefully

**Library and Special JS Features**

The benchmark uses the `forEach` method, which is a standard JavaScript method that iterates over arrays. No special libraries or features are required for this benchmark.

**Considerations**

When choosing between these approaches, consider the following:

* Readability and maintainability: If you prefer a more explicit and readable approach, use `Object.assign`. If you prioritize conciseness and simplicity, direct assignment might be sufficient.
* Performance: For large datasets or performance-critical applications, `Object.assign` might provide a slight edge due to its optimized implementation.

**Alternative Approaches**

If you're interested in exploring alternative approaches, consider the following:

1. **Using `map()`**: Instead of `forEach`, you could use `Array.prototype.map()` to create a new array with transformed objects.
2. **Using loops**: You could also use traditional `for` loops or `while` loops to iterate over the array and assign values to each object.
3. **Closures**: Another approach would be to define a closure function that takes each element of the array as an argument, similar to direct assignment.

Keep in mind that these alternatives might change the performance characteristics of the benchmark or affect its results.

Related benchmarks:

Object.assign template vs direct assignment (version: 0)

Comparing performance of: Direct Assignment vs Object.assign template

Created: 4 years ago by: Guest

Jump to the latest result

Direct Assignment

Object.assign template

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):