Benchmark: Object.assign vs inner for

Script Preparation code:

var queue = [];

for (let i = 0; i < 500; i++) {
    const obj = {
        id: i + 1,
        name: 'John Doe',
        age: Math.floor(Math.random() * 50) + 20,
    };

    // Add random keys with random values
    obj[`key${Math.floor(Math.random() * 50)}`] = Math.random() * 100;
    obj[`key${Math.floor(Math.random() * 50)}`] = Math.random() * 100;

    // Add some objects with repetitive keys
    if (i % 2 === 0) {
        obj.address = {
            street: '123 Main St',
            city: 'Anytown',
            state: 'CA',
            zip: '12345',
        };
    } else {
        obj.address = {
            street: '456 Oak Ave',
            city: 'Somewhere',
            state: 'NY',
            zip: '67890',
        };
    }

    queue.push(obj);
}

var existingObj = {
    id: 24,
    model: 'Ford',
}

Tests:

object assign
for (let i = 0; i < queue.length; i++) { existingObj = Object.assign(existingObj, queue[i]); }
Inner for loop
for(let i = 0; i < queue.length; i++) { for(let key in queue[i]) { if(queue[i][key] !== undefined) { existingObj[key] = queue[i][key] } } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
object assign
Inner for loop

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 provided benchmark and explain what is being tested, compared, and their pros and cons.

**Benchmark Overview**

The benchmark compares two approaches to merge an array of objects into a single object:

1. **Object.assign**: This method creates a new object with specified key-value pairs taken from one or more source objects.
2. **Inner for loop**: This approach iterates through each object in the array, and for each object, it iterates through its keys and assigns values to the corresponding keys in the target object.

**Script Preparation Code**

The script preparation code generates an array of objects (`queue`) with varying properties. Each object has a unique ID, name, age, and sometimes additional random keys. The number of objects in the array is 500.

**Html Preparation Code (null)**

There is no HTML preparation code provided, which means that only JavaScript code is executed for the benchmark.

**Individual Test Cases**

The benchmark consists of two test cases:

1. **"object assign"`**: This test case uses the `Object.assign` method to merge the objects in the `queue` array into a single object (`existingObj`).
2. **"Inner for loop"`**: This test case iterates through each object in the `queue` array using an inner for loop, and then assigns values from each object to the corresponding keys in the `existingObj`.

**Library**

There is no explicitly mentioned library used in this benchmark. However, it's worth noting that the `Object.assign` method is a built-in JavaScript method.

**Special JS Feature or Syntax**

There are no special JavaScript features or syntaxes being tested in this benchmark.

**Pros and Cons of Each Approach**

1. **Object.assign**
	* Pros:
		+ Efficient and concise way to merge objects.
		+ Supports merging multiple source objects into a single target object.
	* Cons:
		+ Can be slower than the inner for loop approach due to the overhead of creating a new object.
		+ May not work as expected if the source objects have different property types or orders.
2. **Inner for loop**
	* Pros:
		+ Allows for more control over the merging process, including handling complex cases like nested objects.
		+ Can be faster than `Object.assign` due to the avoidance of object creation overhead.
	* Cons:
		+ More verbose and less concise than `Object.assign`.
		+ Requires explicit iteration through each object in the array.

**Other Alternatives**

If you're looking for alternative approaches, consider:

1. **Using a library like Lodash**: Lodash provides a `merge` function that can be used to merge objects, which might offer better performance and flexibility than `Object.assign`.
2. **Using a custom implementation**: You could write your own custom merging function using JavaScript's built-in object methods (e.g., `Object.keys()`, `forEach()`). This would allow you to tailor the merging process to specific requirements.
3. **Using a different data structure**: Depending on the specific use case, alternative data structures like arrays or JSON objects might be more suitable for merging purposes.

In conclusion, this benchmark compares two approaches to merge an array of objects into a single object: `Object.assign` and an inner for loop approach. While both methods have their pros and cons, the choice ultimately depends on the specific requirements and performance characteristics of your application.

Related benchmarks:

Object.assign vs inner for (version: 0)

ASD

Comparing performance of: object assign vs Inner for loop

Created: 3 years ago by: Guest

Jump to the latest result

object assign

Inner for loop

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):