Benchmark: Merging array of objects [Lodash merge vs Array.prototype.reduce merge]

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

var x = null;
var testObjectArray = [{
    a: 1
}, {
    b: 1
}, {
    c: [1, 2, 3]
}, {
    d: "hello"
}, {
    e: "e",
    f: "f"
}];

var reduceMerge = (objectArray) => objectArray.reduce(((accumulator, object) => Object.assign(accumulator, object)))

Tests:

lodash merge spread
x = _.merge(...testObjectArray);
lodash merge loop
x = {} for(const object in testObjectArray) { x = _.merge(x, object); }
reduce merge
x = reduceMerge(testObjectArray);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash merge spread
lodash merge loop
reduce merge

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36

Browser/OS: Chrome 133 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
lodash merge spread	1682741.2 Ops/sec
lodash merge loop	211380.0 Ops/sec
reduce merge	7370503.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, compared, and other considerations.

**Benchmark Test Case:**

The test case is comparing three approaches to merging an array of objects:

1.  `reduceMerge` function
2.  Lodash's `merge` function with spread syntax (`_.merge(...testObjectArray)`)
3.  Lodash's `merge` function using a loop (`for(const object in testObjectArray) { x = _.merge(x, object); }`)

**Options Compared:**

The benchmark is comparing the performance of three different approaches to merge an array of objects:

*   **Lodash's `merge` function with spread syntax**: This approach uses the spread operator (`...`) to pass multiple arguments to the `merge` function.
*   **Lodash's `merge` function using a loop**: This approach uses a `for` loop to iterate over the array and merge each object into a single accumulator.
*   **Custom `reduceMerge` function**: This is a custom implementation that uses the `reduce` method to merge an array of objects.

**Pros and Cons:**

*   **Lodash's `merge` function with spread syntax**:
    *   Pros:
        *   Concise and readable code
        *   Easy to understand for developers familiar with Lodash
    *   Cons:
        *   May not be optimized for performance
        *   Can lead to slower execution due to the overhead of creating a new array with spread operators
*   **Lodash's `merge` function using a loop**:
    *   Pros:
        *   Optimized for performance due to using a loop instead of recursion or array methods
        *   Easy to understand and implement
    *   Cons:
        *   Code may not be as concise or readable compared to the spread syntax approach
*   **Custom `reduceMerge` function**:
    *   Pros:
        *   Optimized for performance due to using the `reduce` method
        *   Can provide better control over the merging process
    *   Cons:
        *   May be harder to understand and implement compared to Lodash's `merge` function
        *   Requires knowledge of the `reduce` method

**Library Used:**

Lodash is a popular JavaScript library that provides utility functions for functional programming. In this case, it's being used for its `merge` function.

**Special JS Feature or Syntax:**

The benchmark doesn't use any special JavaScript features or syntax beyond what's standard in modern JavaScript. However, it does demonstrate the use of Lodash's `merge` function and its spread syntax feature.

**Other Alternatives:**

If you're interested in exploring alternative approaches to merging arrays of objects, here are a few options:

*   **Vanilla JavaScript**: You can implement your own merge function using vanilla JavaScript without relying on libraries like Lodash.
*   **Array.prototype.reduce()**: Like the custom `reduceMerge` function, you can use the `reduce()` method to merge an array of objects.
*   **Other library functions**: Depending on the specific requirements and constraints of your project, you might consider using other library functions, such as `immer` or `console.log`, for merging arrays of objects.

In summary, this benchmark is comparing three approaches to merging an array of objects: Lodash's `merge` function with spread syntax, its `merge` function using a loop, and a custom implementation using the `reduce` method. The results will help identify which approach performs best in terms of execution speed.

Related benchmarks:

Merging array of objects [Lodash merge vs Array.prototype.reduce merge] (version: 0)

Comparing performance of: lodash merge spread vs lodash merge loop vs reduce merge

Created: 5 years ago by: Guest

Jump to the latest result

lodash merge spread

lodash merge loop

reduce merge

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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