Benchmark: Delete from object, existence check

Script Preparation code:

var obj = {
    "one": null,
    "two": null,
}

Tests:

Delete Existing, No Check
delete obj["two"]
Delete Existing, Check
if (obj["two"] !== undefined) { delete obj["two"] }
Delete Nonexisting, No Check
delete obj["three"]
Delete Nonexisting, Check
if (obj["two"] !== undefined) { delete obj["three"] }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Delete Existing, No Check
Delete Existing, Check
Delete Nonexisting, No Check
Delete Nonexisting, Check

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.

**Benchmark Overview**

The provided JSON represents a JavaScript benchmark test case on MeasureThat.net. The goal of this benchmark is to compare the performance of different approaches for deleting a property from an object in JavaScript.

**Script Preparation Code**

The script preparation code defines an object `obj` with two properties, `"one"` and `"two"`, both initialized as `null`.

```javascript
var obj = {
    "one": null,
    "two": null
}
```

This setup is used as a common base for all test cases.

**Test Cases**

There are four individual test cases:

1. **Delete Existing, No Check**
```javascript
delete obj["two"]
```
This test case deletes the `"two"` property from the `obj` object without performing any existence checks.

2. **Delete Existing, Check**
```javascript
if (obj["two"] !== undefined) {
    delete obj["two"]
}
```
This test case first checks if the `"two"` property exists in the `obj` object and only then deletes it.

3. **Delete Nonexisting, No Check**
```javascript
delete obj["three"]
```
This test case attempts to delete a non-existent property `"three"` from the `obj` object without performing any existence checks.

4. **Delete Nonexisting, Check**
```javascript
if (obj["two"] !== undefined) {
    delete obj["three"]
}
```
This test case first checks if the `"two"` property exists in the `obj` object and only then attempts to delete a non-existent property `"three"`.

**Library: None**

There are no external libraries used in these benchmark test cases.

**Special JS Feature/Syntax: None**

None of the provided test cases utilize any special JavaScript features or syntax, such as async/await, Promises, or modern ES6+ features.

**Performance Comparison**

The benchmark tests the performance of deleting a property from an object using two approaches:

1. **Direct Deletion**: Deleting the property directly without existence checks (Test Case 1 and 3).
2. **Existence Check**: Performing an existence check before deletion (Test Cases 2 and 4).

The results show that direct deletion without existence checks is generally faster than performing an existence check.

**Pros and Cons**

* **Direct Deletion**:
	+ Pros: Faster performance, as it avoids the overhead of an existence check.
	+ Cons: May cause errors if the property does not exist.
* **Existence Check**:
	+ Pros: Prevents errors by checking for the existence of the property before deletion.
	+ Cons: Slower performance due to the additional overhead of the existence check.

**Alternatives**

Other approaches for deleting a property from an object in JavaScript include:

1. Using `in` operator to check for property existence, e.g., `if ("two" in obj) { delete obj["two"] }`.
2. Using `hasOwnProperty()` method on the prototype chain, e.g., `if (obj.hasOwnProperty("two")) { delete obj["two"] }`.
3. Using `Object.prototype.hasOwnProperty.call()` to check for property existence, e.g., `if (Object.prototype.hasOwnProperty.call(obj, "two")) { delete obj["two"] }`.

However, these alternatives may not provide the same performance benefits as direct deletion without existence checks.

Related benchmarks:

Delete from object, existence check (version: 0)

Comparing performance of: Delete Existing, No Check vs Delete Existing, Check vs Delete Nonexisting, No Check vs Delete Nonexisting, Check

Created: 4 years ago by: Registered User

Jump to the latest result

Delete Existing, No Check

Delete Existing, Check

Delete Nonexisting, No Check

Delete Nonexisting, Check

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):