Benchmark: array flatten - MeasureThat.net

Script Preparation code:

function spliceFlatten(arr) {
    for (var i = 0; i < arr.length; ++i) {
      if (Array.isArray(arr[i])) {
        // need to add i and 1 as arguments to the real splice command,
        // plus all the values of arr[i]
        arr[i].splice(0, 0, i, 1);
        Array.prototype.splice.apply(arr, arr[i]);
  
        // Check for more inner arrays at beginning of this array
        --i;
      }
    }
  
    return arr;
  }

function copySpliceFlatten(arr) {
  arr = arr.slice(0);
    for (var i = 0; i < arr.length; ++i) {
      if (Array.isArray(arr[i])) {
        arr[i] = arr[i].slice(0);
        // need to add i and 1 as arguments to the real splice command,
        // plus all the values of arr[i]
        arr[i].splice(0, 0, i, 1);
        Array.prototype.splice.apply(arr, arr[i]);
  
        // Check for more inner arrays at beginning of this array
        --i;
      }
    }
  
    return arr;
  }

var a = [1, [2, 3],
    [
      [
        [
          [4]
        ]
      ], 5
    ]
  ];
  var b = [1, 2];
  var c = [1, [
    [
      [
        [
          [
            [2]
          ]
        ]
      ]
    ]
  ]];
  var d = [
    ["$6"],
    ["$12"],
    ["$25"],
    ["$25"],
    ["$18"],
    ["$22"],
    ["$10"],
    ["$0"],
    ["$15"],
    ["$3"],
    ["$75"],
    ["$5"],
    ["$100"],
    ["$7"],
    ["$3"],
    ["$75"],
    ["$5"]
  ];

Tests:

spliceFlatten
spliceFlatten(a); spliceFlatten(b); spliceFlatten(c); spliceFlatten(d);
copySpliceFlatten
copySpliceFlatten(a); copySpliceFlatten(b); copySpliceFlatten(c); copySpliceFlatten(d);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spliceFlatten
copySpliceFlatten

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 dive into the world of JavaScript microbenchmarks and explore what's being tested on MeasureThat.net.

**Benchmark Overview**

The benchmark measures the performance of two approaches to flatten an array: `spliceFlatten` and `copySpliceFlatten`. The input arrays are created with varying levels of nesting, including inner arrays and strings. The goal is to determine which approach is faster for this specific use case.

**Options Compared**

There are only two options being compared:

1. **spliceFlatten**: This function uses the `Array.prototype.splice` method to flatten the array. It iterates through each element in the array, checks if it's an inner array, and then uses `splice` to add the index of the outer array and a dummy value (1) at the beginning of the inner array. The resulting array is then flattened by applying `Array.prototype.splice` again.
2. **copySpliceFlatten**: This function creates a copy of the original array using `arr = arr.slice(0);`. It then iterates through each element in the array, checks if it's an inner array, and uses `splice` to add the index of the outer array and a dummy value (1) at the beginning of the inner array. The resulting array is then flattened by applying `Array.prototype.splice` again.

**Pros and Cons**

Both approaches have their trade-offs:

* **spliceFlatten**:
	+ Pros: Uses built-in methods, potentially faster execution.
	+ Cons: May cause performance issues if not implemented correctly (e.g., modifying the original array).
* **copySpliceFlatten**:
	+ Pros: Creates a copy of the original array, avoids potential modification issues.
	+ Cons: Requires more memory allocation and copying.

**Library Used**

There is no external library used in these functions. They rely on built-in JavaScript methods (`Array.prototype.splice`).

**Special JS Feature or Syntax**

None mentioned explicitly, but it's worth noting that both approaches use the `splice` method, which might not be optimized for all browsers or versions. Additionally, the use of `--i;` in the loop counter is a common optimization technique to avoid overflow issues.

**Other Alternatives**

Alternative approaches could include:

* Using a library like Lodash or Ramda, which provides functional programming utilities and can simplify array manipulation.
* Implementing a recursive approach with explicit stack management to flatten the arrays.
* Utilizing modern JavaScript features like `flat()` (ES6+) or `flatMap()` (ES11+), if supported by the target browsers.

For this specific benchmark, MeasureThat.net's focus on simple, straightforward implementation and minimal external dependencies makes sense. However, for more complex use cases or larger datasets, alternative approaches might be necessary to optimize performance or memory usage.

Related benchmarks:

array flatten (version: 0)

Comparing performance of: spliceFlatten vs copySpliceFlatten

Created: 8 years ago by: Registered User

Jump to the latest result

spliceFlatten

copySpliceFlatten

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):