Benchmark: [0] vs .shift() with empty array

Tests:

1
const array = [] array[0]
2
const array = [] array.shift()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
1
2

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.36

Browser/OS: Chrome 123 on Linux

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Test name	Executions per second
1	179900416.0 Ops/sec
2	98261432.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to explain the benchmark and its test cases.

**What is tested?**

The provided JSON represents two microbenchmarks that compare the performance of accessing an element in an array using traditional indexing (`array[0]`) versus using the `shift()` method, which removes the first element from the array without returning a value. The goal is to determine which approach is faster for creating and then modifying an empty array.

**Options compared**

Two options are compared:

1. **Traditional indexing**: Using square brackets `[]` to access an element in the array, as shown in the benchmark definition: `"const array = []\r\narray[0]"`.
2. **`shift()` method**: Using the `shift()` method to remove the first element from the array without returning a value, as shown in the benchmark definition: `"const array = []\r\narray.shift()"`.

**Pros and cons of each approach**

1. **Traditional indexing**:
	* Pros:
		+ Faster execution time since it doesn't require additional operations like `shift()`.
		+ Less overhead compared to the `shift()` method.
	* Cons:
		+ May not be as efficient if the array is large, since accessing an element at a specific index can lead to slower performance due to the language's indexing mechanism.
2. **`shift()` method**:
	* Pros:
		+ Can be more efficient for creating and then modifying an empty array, especially when dealing with large arrays, as it avoids the overhead of indexing.
	* Cons:
		+ Slower execution time compared to traditional indexing since it involves removing the first element from the array.

**Library usage**

None of the provided benchmark code uses a library. However, it's worth noting that libraries like Lodash or others may provide optimized implementations for array manipulation and indexing, which could impact performance.

**Special JS features or syntax**

There are no special JavaScript features or syntax mentioned in the benchmark code. The test cases only involve basic array operations using `[]` and the `shift()` method.

**Alternative approaches**

Other alternatives to compare with traditional indexing and the `shift()` method might include:

1. **Array slicing**: Creating a new array by slicing an existing array, e.g., `"const array = []\r\nconst newArray = array.slice(0, 1)"`.
2. **Array destructuring**: Using destructuring syntax to extract the first element from an empty array, e.g., `"const [firstElement] = []"`.

Keep in mind that these alternatives might have different performance characteristics and may not be directly comparable to traditional indexing and the `shift()` method without additional analysis.

Related benchmarks:

[0] vs .shift() with empty array (version: 0)

Comparing performance of: 1 vs 2

Created: 2 years ago by: Guest

Jump to the latest result

1

2

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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