Benchmark: object readings - MeasureThat.net

Script Preparation code:

function fn1(o) {
  const len = o.length
  return "[" + len + "] " + len
}

function fn2(o) {
  return "[" + o.length + "] " + o.length
}

Tests:

single
fn1([]) fn1([1, 2, 3]) fn1({}) fn1({ length: 1e6 })
double
fn2([]) fn2([1, 2, 3]) fn2({}) fn2({ length: 1e6 })

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
single
double

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 definition and test cases.

**Benchmark Definition JSON**

The benchmark definition is a simple JavaScript function that calculates the length of an object or array, and returns it as a string. The two functions `fn1` and `fn2` are identical, except for the way they calculate the length. In `fn1`, the length is calculated using the `length` property, while in `fn2`, it's calculated directly by taking the number of elements (using `o.length`).

The script preparation code defines these two functions:

```javascript
function fn1(o) {
  const len = o.length;
  return "[ " + len + "] " + len;
}

function fn2(o) {
  return "[ " + o.length + "] " + o.length;
}
```

**Options Compared**

In this benchmark, we have two options for calculating the length of an object or array:

1. `fn1`: calculates the length using the `length` property (`o.length`).
2. `fn2`: calculates the length directly by taking the number of elements (using `o.length`).

**Pros and Cons**

* **Pro of `fn1`**: It's a simple and straightforward way to calculate the length, as it leverages the built-in `length` property.
* **Con of `fn1`**: However, this approach can be slow for large arrays or objects, as it involves creating a new string and concatenating it with the length value. This can lead to unnecessary memory allocations and function calls.
* **Pro of `fn2`**: On the other hand, `fn2` is a more concise way to calculate the length, which might be faster for large inputs due to fewer operations.

However, there's a trade-off: since we're using the same syntax (`o.length`) in both cases, this optimization might not have a significant impact on performance. In contrast, if we were using different calculations or data structures, this difference could become more pronounced.

**Library and Special JS Features**

There are no libraries used in this benchmark. Additionally, there are no special JavaScript features (e.g., ES6+ syntax, async/await, etc.) that require specific handling.

**Alternative Approaches**

Some alternative approaches to calculating the length of an object or array include:

* Using a library like Lodash (`_.size()`), which provides a convenient and efficient way to calculate lengths.
* Implementing a custom length calculation using a data structure like a trie or a balanced binary search tree, which can potentially outperform simple string concatenation.

However, these alternatives would likely introduce additional dependencies or complexity, so it's essential to carefully evaluate the benefits and trade-offs before switching from the current implementation.

Related benchmarks:

object readings (version: 0)

Comparing performance of: single vs double

Created: 4 years ago by: Registered User

Jump to the latest result

single

double

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):