Benchmark: Updating objects w spread

Script Preparation code:

setC = (v, o) => ({
  a: o.a,
  b: o.b,
  c: v,
  d: o.d,
  e: o.e,
  f: o.f,
  g: o.g,
  h: o.h,
  i: o.i,
  j: o.j,
  k: o.k,
  l: o.l,
  m: o.m,
  n: o.n,
  o: o.o,
  p: o.p,
  q: o.q,
  r: o.r,
  s: o.s,
  t: o.t,
  u: o.u,
  v: o.v,
  w: o.w,
  x: o.x,
  y: o.y,
  z: o.z
})

o = {
  a: 1,
  b: 2,
  c: 3,
  d: 4,
  e: 5,
  f: 6,
  g: 7,
  h: 8,
  i: 9,
  j: 10,
  k: 11,
  l: 12,
  m: 13,
  n: 14,
  o: 15,
  p: 16,
  q: 17,
  r: 18,
  s: 19,
  t: 20,
  u: 21,
  v: 22,
  w: 23,
  x: 24,
  y: 25,
  z: 26
};

Tests:

Assign
assign = Object.assign({}, o, {c: 4});
Spread
spread = {...o, c: 4};
Literal
literal = setC(4, o)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Assign
Spread
Literal

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 options, pros and cons of those approaches, and other considerations.

**Benchmark Definition JSON**

The benchmark defines an object `o` with 26 properties, each initialized to a consecutive integer from 1 to 26. The script preparation code, `setC`, creates a new object that assigns values to all properties of the original object `o`, including the new property `c` with value 4.

**Individual Test Cases**

There are three test cases:

1. **Assign**: `assign = Object.assign({}, o, {c: 4});`
This test case uses the `Object.assign()` method to create a new object that assigns all properties from the original object `o` and adds a new property `c` with value 4.
2. **Spread**: `spread = {...o, c: 4};`
This test case uses the spread operator (`...`) to create a new object that copies all properties from the original object `o` and adds a new property `c` with value 4.
3. **Literal**: `literal = setC(4, o)`
This test case calls the `setC()` function with two arguments: `4` (the value to assign to the new property) and `o` (the original object).

**Options Compared**

The three test cases compare different approaches to creating a new object that assigns values to all properties of the original object:

* **Assign**: uses `Object.assign()`
* **Spread**: uses the spread operator (`...`)
* **Literal**: uses the `setC()` function with two arguments

**Pros and Cons of Each Approach**

1. **Assign**: Pros:
	+ Can be used with objects that have many properties, as it can assign all properties in a single operation.
	* Cons: May be slower than spread or literal approaches for small objects due to the overhead of `Object.assign()`.
2. **Spread**: Pros:
	+ Fast and efficient, especially for small objects.
	* Cons: May not work correctly if the object has many properties that are not enumerable (i.e., not visible in the `for...in` loop).
3. **Literal**: Pros:
	+ Can be used with objects that have non-enumerable properties, as it uses a function to create a new object.
	* Cons: May be slower than spread or assign approaches due to the overhead of creating and calling the `setC()` function.

**Library Used**

The `Object.assign()` method is part of the JavaScript standard library, which means that all modern browsers support it. The spread operator (`...`) is also a part of the JavaScript standard library.

**Special JS Feature or Syntax**

None of the test cases use any special JavaScript features or syntax, apart from using object literals and function declarations (in the case of `setC()`).

**Other Considerations**

When choosing an approach, consider the following factors:

* **Performance**: For small objects, spread may be faster. For larger objects, assign may be faster.
* **Readability**: Spread can make code more readable for some developers, while assign or literal approaches may make it harder to understand what's happening.
* **Correctness**: Ensure that the chosen approach works correctly with all properties of the object, including non-enumerable ones.

**Alternatives**

Other alternatives to these test cases could include:

* Using a library like Lodash or Underscore.js, which provide utility functions for working with objects.
* Using a different approach, such as using `Object.create()` and then assigning values to each property individually.
* Using a modern JavaScript feature like `new.target` to create a new object and assign values.

Related benchmarks:

Updating objects w spread (version: 0)

Comparing performance of: Assign vs Spread vs Literal

Created: 7 years ago by: Guest

Jump to the latest result

Assign

Spread

Literal

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):