Benchmark: spread operator VS delete

Script Preparation code:

var user = {
id: 1,
    name: 'Hamed',
    gender: 'male',
  email: 'johndoe@example.com',
  address: {
    street: '123 Main Street',
    city: 'Anytown',
    state: 'ABC',
    country: 'XYZ'
  },
  hobbies: ['reading', 'coding', 'gaming'],
  education: [
    {
      degree: 'Bachelor of Science',
      major: 'Computer Science',
      university: 'ABC University',
      year: 2015
    },
    {
      degree: 'Master of Business Administration',
      major: 'Business Management',
      university: 'XYZ University',
      year: 2019
    }
  ],
  projects: {
    project1: {
      name: 'Project A',
      description: 'Lorem ipsum dolor sit amet, consectetur adipiscing elit.',
      startDate: '2020-01-01',
      endDate: '2021-12-31'
    },
    project2: {
      name: 'Project B',
      description: 'Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.',
      startDate: '2022-01-01',
      endDate: '2023-06-30'
    }
  }
    
}

Tests:

imutable - spread operator
const {gender, ...newUser} = user;
imutable assign - delete
const newUser = Object.assign({}, user); delete newUser.gender
imutable spread operator - delete
const newUser = { ...user } delete newUser.gender
imutable stringify - delete
const newUser = JSON.parse(JSON.stringify(user)); delete newUser.gender
mutable - delete
delete user.gender

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
imutable - spread operator
imutable assign - delete
imutable spread operator - delete
imutable stringify - delete
mutable - delete

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

The provided benchmark measures the performance difference between various methods of deleting properties from an object in JavaScript.

**Methods Compared**

1. **Immutable Spread Operator**: `const {gender, ...newUser} = user;` - This method uses the spread operator to create a new object with all properties except `gender`.
2. **Immutable Assign**: `const newUser = Object.assign({}, user); delete newUser.gender;` - This method creates a shallow copy of the original object using `Object.assign()` and then deletes the `gender` property.
3. **Immutable Spread Operator with Delete**: `const newUser = { ...user } delete newUser.gender;` - Similar to the previous method, but uses the spread operator again to create a new object with all properties except `gender`.
4. **Immutable Stringify**: `const newUser = JSON.parse(JSON.stringify(user)); delete newUser.gender;` - This method serializes and deserializes the original object using `JSON.parse()` and `JSON.stringify()`, which creates a deep copy of the object.
5. **Mutable Delete**: `delete user.gender;` - This is a simple delete statement on the original object.

**Pros and Cons**

1. **Immutable Spread Operator**: Pros: concise, efficient. Cons: only copies properties that are not deleted, may not work as expected with complex objects or nested properties.
2. **Immutable Assign**: Pros: creates a deep copy of the entire object, can handle complex objects and nested properties. Cons: less efficient than the spread operator method, uses more memory to create a new object.
3. **Immutable Spread Operator with Delete**: Similar pros and cons as the first method.
4. **Immutable Stringify**: Pros: creates a deep copy of the entire object, handles complex objects and nested properties. Cons: serializes/deserializes the object, may be slower than other methods.
5. **Mutable Delete**: Pros: simple, fast. Cons: modifies the original object, can lead to unexpected behavior if not used carefully.

**Library Usage**

None of the provided methods rely on any external libraries.

**Special JS Features/Syntax**

- None mentioned in the benchmark definition.

**Alternative Approaches**

1. Using `Object.assign()` with an empty object to create a shallow copy and then deleting properties: `const newUser = Object.assign({}, user); delete newUser.gender;`
2. Using `for...in` loop to iterate over object properties and delete them one by one.
3. Using `delete` operator with a property name, like `delete user.gender;`, which is equivalent to the mutable delete approach but can be more efficient in some cases.

These alternatives are not included in the benchmark results, as they were not specified in the provided code.

Latest run results:

Run details: (Test run date: 6 days ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36 OPR/114.0.0.0

Browser/OS: Opera 114 on Linux

View result in a separate tab

Test name	Executions per second
imutable - spread operator	8020452.0 Ops/sec
imutable assign - delete	3694964.2 Ops/sec
imutable spread operator - delete	5852674.0 Ops/sec
imutable stringify - delete	447938.2 Ops/sec
mutable - delete	21800026.0 Ops/sec

Related benchmarks:

spread operator VS delete (version: 2)

Comparing the performance difference between the spread operator and the delete operator.

Comparing performance of: imutable - spread operator vs imutable assign - delete vs imutable spread operator - delete vs imutable stringify - delete vs mutable - delete

Created: one year ago by: Registered User

Jump to the latest result

imutable - spread operator

imutable assign - delete

imutable spread operator - delete

imutable stringify - delete

mutable - delete

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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