Benchmark: Object.hasOwnProperty vs Object in vs Object[] vs Array.indexOf vs Array.includes1231231

Script Preparation code:

  var object = {},
      array = [],
      i, test = 1000;
  
  for (i = 0; i < 1000; i++) {
   object['something' + i] = true;
   array.push('something' + i);
  }

Tests:

Object.hasOwnProperty
object.hasOwnProperty('something' + test)
Object in
('something' + test) in object
Array.indexOf
array.indexOf('something' + test) !== -1
direct
object['something' + test] === true
Array includes
array.includes('something' + test)
has
Object.hasOwn(object, 'something' + test)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.hasOwnProperty
Object in
Array.indexOf
direct
Array includes
has

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and its test cases, explaining what's being tested, compared options, pros/cons, and other considerations.

**Benchmark Overview**

The benchmark measures the performance of different approaches for checking if a property exists in an object or array. It creates a large object and array with 1000 properties/elements, then uses each test case to check if a randomly generated string is present in the object/array.

**Test Cases**

1. **Object.hasOwnProperty**: Checks if the string 'something' + test exists as a property of the object using the `hasOwnProperty` method.
2. **Object in**: Checks if the string 'something' + test is a key in the object using the `in` operator.
3. **Array.indexOf**: Searches for the string 'something' + test in the array using the `indexOf` method.
4. **direct**: Directly checks if the value of `object['something' + test]` equals `true`.
5. **Array includes**: Checks if the string 'something' + test is included in the array using the `includes` method.
6. **has**: Same as `Object.hasOwnProperty`.

**Comparison**

The benchmark compares the performance of these six approaches:

* `Object.hasOwnProperty`: Uses the `hasOwnProperty` method to check for property existence.
* `Object in`: Uses the `in` operator to check if a key exists.
* `Array.indexOf`: Searches for the string using the `indexOf` method.
* `direct`: Directly accesses the object/array element.
* `Array includes`: Checks if the string is included in the array.
* `has`: Same as `Object.hasOwnProperty`.

**Pros and Cons**

1. **Object.hasOwnProperty**:
	* Pros: More efficient for large objects with many properties, as it only checks the property's own prototype chain.
	* Cons: May be slower for small objects or arrays with few elements.
2. **Object in**:
	* Pros: Faster than `hasOwnProperty` for small objects and arrays.
	* Cons: May be less accurate due to potential caching issues.
3. **Array.indexOf**:
	* Pros: Fast for large arrays, but can be slower for small arrays or objects.
	* Cons: Returns -1 if the element is not found, which may lead to unnecessary checks.
4. **direct**:
	* Pros: Simple and fast, but may cause issues with object/array access patterns.
	* Cons: May not handle errors or out-of-bounds accesses well.
5. **Array includes**:
	* Pros: Fast and efficient for arrays.
	* Cons: May be slower for very large arrays due to the need to iterate over elements.
6. **has**:
	* Pros: Same as `Object.hasOwnProperty`.
	* Cons: No additional benefits.

**Other Considerations**

* The benchmark assumes that the object/array is not too large, which may impact performance.
* Caching issues might arise with the `in` operator, especially in older browsers.
* Direct access to array elements can lead to issues with out-of-bounds accesses or errors.
* Using `includes` on very large arrays may be slower due to iteration.

**Alternatives**

If you need alternative approaches, consider:

* **Object.keys()**: Returns an array of property names. Can be used for fast and efficient property existence checks in modern browsers.
* **Array.prototype.includes()` with a custom implementation: Allows for fine-grained control over the search algorithm.
* **For-in loops**: Manual iteration over object/array properties can provide better performance but may require more code and maintenance.

Keep in mind that these alternatives might not be available or supported by all browsers, so consider the target environment when choosing an approach.

Related benchmarks:

Object.hasOwnProperty vs Object in vs Object[] vs Array.indexOf vs Array.includes1231231 (version: 0)

Comparing performance of: Object.hasOwnProperty vs Object in vs Array.indexOf vs direct vs Array includes vs has

Created: 2 years ago by: Guest

Jump to the latest result

Object.hasOwnProperty

Object in

Array.indexOf

direct

Array includes

has

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):