Benchmark: delete vs null vs undefined vs void 0 vs Object.create(null)2

Tests:

null
var a = undefined for(var i = 0; i < 1000;i++) { if (a === null) { } }
undefined
var a = undefined; for(var i = 0; i < 1000;i++) { if (a === undefined) {}; }
Object.create(null)
var a = undefined; for(var i = 0; i < 1000;i++) { a = void 0; }
void 0
var a = 999; for(var i = 0; i < 1000;i++) { a = void 0; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
null
undefined
Object.create(null)
void 0

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.

Measuring the performance of different approaches to deleting or replacing a variable in JavaScript can be an interesting benchmark.

**What is being tested?**

The provided JSON represents four individual test cases that compare the performance of the following approaches:

1. `delete` ( deleting a variable)
2. `null` (assigning null to a variable)
3. `undefined` (assigning undefined to a variable)
4. `void 0` (assigning undefined using the old syntax `void 0`)
5. `Object.create(null)` (creating an object with no prototype, which is equivalent to assigning `undefined`)

The test cases are designed to iterate over a large number of iterations (`1000`) and measure the time it takes to execute each approach.

**Options compared**

Here's a brief overview of what each option does:

* `delete`: removes the variable from the current scope
* `null`: assigns null to the variable, which has no effect on its value
* `undefined`: assigns undefined to the variable, which is equivalent to deleting it in some browsers
* `void 0`: assigns undefined using the old syntax. This is a deprecated way of assigning undefined.
* `Object.create(null)`: creates an object with no prototype, which is equivalent to assigning `undefined` to the variable.

**Pros and Cons**

Here are some pros and cons of each approach:

* `delete`: Good performance, but not supported in all browsers
* `null`: Fast and reliable, but doesn't delete the variable
* `undefined`: Can be faster than `delete`, but behavior varies across browsers
* `void 0`: Old syntax with varying support across browsers (not recommended)
* `Object.create(null)`: Creates an object with no prototype, which is equivalent to assigning `undefined`. Performance is similar to `null`.

**Other considerations**

The performance of these approaches can vary depending on the JavaScript engine and browser being used. Additionally, some browsers may optimize away certain instructions or have specific rules for variable deletion.

**Library usage**

In none of the provided test cases does a library explicitly define any functionality. However, it's worth noting that some libraries, such as `lodash` or `ramda`, might provide optimized implementations of variable deletion.

**Special JS features or syntax**

There are no special JavaScript features or syntax used in these benchmarks. The focus is solely on comparing the performance of different approaches to deleting a variable.

**Alternatives**

If you're interested in exploring more options, you could consider adding test cases for:

* `delete` using a function (e.g., `function foo() { delete bar; }`)
* Using a library like `lodash` or `ramda` for optimized variable deletion
* Checking the execution plan of each browser to see if it optimizes away any instructions

Keep in mind that these alternatives might add complexity and require additional resources.

Related benchmarks:

delete vs null vs undefined vs void 0 vs Object.create(null)2 (version: 0)

delete vs null vs undefined vs void 0 vs Object.create(null)

Comparing performance of: null vs undefined vs Object.create(null) vs void 0

Created: 7 years ago by: Guest

Jump to the latest result

null

undefined

Object.create(null)

void 0

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):