Benchmark: Object.assign vs Direct Assignment #2

Script Preparation code:

var data = {};

Tests:

Direct Assignment
for(var i = 0; i < 10000; i++) { data[`prop_${i}`] = true; }
Object.assign
for(var i = 0; i < 10000; i++) { Object.assign(data, { [`prop_${i}`]: true }); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Direct Assignment
Object.assign

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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I'll explain the benchmark in detail.

**Benchmark Overview**

The benchmark is designed to compare two approaches for assigning properties to an object: direct assignment using dot notation (`data[`prop_${i}`] = true;`) and using `Object.assign()`. The benchmark measures which approach is faster, specifically when adding 10,000 properties with a unique name (`prop_0`, `prop_1`, ..., `prop_9999`).

**Options Compared**

The two options compared are:

1. **Direct Assignment**: This approach uses dot notation to assign values directly to the object's properties. For example: `data[`prop_${i}`] = true;`.
2. **Object.assign()**: This approach uses the `Object.assign()` method to add new properties to an existing object. The syntax is: `Object.assign(data, { [`prop_${i}`]: true });`.

**Pros and Cons**

### Direct Assignment

Pros:

* Faster and more efficient since it avoids the overhead of a function call
* Typically faster for simple assignments

Cons:

* Can lead to slower performance when working with large numbers of properties due to string concatenation (e.g., `data[`prop_${i}`] = true;`)
* May not be as readable or maintainable, especially in complex scenarios

### Object.assign()

Pros:

* More readable and maintainable, as it clearly separates the source data from the target object
* Can be more efficient when working with large amounts of data, since it avoids string concatenation

Cons:

* Slower due to the overhead of a function call
* May incur additional memory allocations or copies if not handled properly

**Library/Additional Considerations**

In this benchmark, there is no library used explicitly. However, the `Object` class and its methods (`assign()`, etc.) are part of the JavaScript standard library.

No special JavaScript features or syntax are mentioned in the provided code.

**Other Alternatives**

If you're interested in exploring alternative approaches:

1. **Array.prototype.forEach()` or a similar loop: These methods can be used to iterate over an array and assign values to an object, but may incur additional overhead due to function call and iteration.
2. **Template literals (e.g., `data`${i} = true;`)**: This approach uses template literals to dynamically generate property names. While it's concise, its performance might not be significantly better than direct assignment.

Keep in mind that these alternatives will likely result in different benchmark results compared to the original test cases.

Related benchmarks:

Object.assign vs Direct Assignment #2 (version: 0)

Comparing performance of: Direct Assignment vs Object.assign

Created: 6 years ago by: Guest

Jump to the latest result

Direct Assignment

Object.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):