Benchmark: xyzabc - MeasureThat.net

Tests:

spread
const events = {}; const a = 'ad'; const c = 'c'; events[c] = [a, ...(events[c] ?? [])]
unshift
const events = {}; const a = 'ad'; const c = 'c'; events[c] = Array.isArray(events[c]) ? events[c].unshift(a) : [a]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread
unshift

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark definition is represented by two JSON objects, each containing information about a specific test case. The common structure among both definitions includes:

* `const events = {};`: Initializes an empty object to store key-value pairs.
* `const a = 'ad';` and `const c = 'c';`: Define two string constants, "a" and "c".
* The difference between the two test cases lies in how the value for `events[c]` is assigned:
	+ In the first test case (`"spread"`), it uses the spread operator (`...`) to concatenate arrays. If `events[c]` is an array, its elements are merged with `[a]`. Otherwise, a new array containing only `[a]` is created.
	+ In the second test case (`"unshift"`), it checks if `events[c]` is an array using the `Array.isArray()` function. If it's an array, `a` is unshifted onto its beginning using the `unshift()` method. Otherwise, a new array containing only `[a]` is created.

**Options Compared**

The two test cases compare the performance of:

1. **Spread Operator (`...`)**: Concatenates arrays element-wise.
2. **Unshift() Method**: Appends elements to the beginning of an array.

**Pros and Cons**

* **Spread Operator (`...`)**:
	+ Pros:
		- Concise and easy to read.
		- Often used for simple concatenations.
	+ Cons:
		- Can be slower than using `unshift()` when dealing with large arrays.
		- May not work as expected if the target array is a string or other non-array type.
* **Unshift() Method**:
	+ Pros:
		- Efficiently appends elements to the beginning of an array.
		- Works well for large arrays and non-string targets.
	+ Cons:
		- May be less readable than using the spread operator.
		- Can be slower than using `...` when dealing with small arrays.

**Library and Purpose**

None are explicitly mentioned in this benchmark. However, the use of JavaScript features like spread operators and array methods is a common occurrence in modern web development.

**Special JS Feature or Syntax**

This benchmark uses two special JavaScript features:

* **Spread Operator (`...`)**: Introduced in ECMAScript 2015 (ES6), allowing for concise array concatenation.
* **Array Methods (`unshift()`, `Array.isArray()`)**: These methods are part of the ECMAScript standard and are commonly used in modern web development.

**Alternatives**

Other alternatives to compare these two approaches include:

1. Using the `concat()` method instead of the spread operator.
2. Comparing the performance of different data structures, such as arrays vs. objects, or using different caching mechanisms.
3. Evaluating the impact of array size on performance.

Please note that this benchmark is likely to measure the overhead of these operations in a specific context (e.g., web development) and might not be representative of all possible use cases.

Related benchmarks:

xyzabc (version: 0)

Comparing performance of: spread vs unshift

Created: 3 years ago by: Guest

Jump to the latest result

spread

unshift

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):