Benchmark: Array vs object - MeasureThat.net

Script Preparation code:

var n = 5;
var a = [];
var obj = {};
for (var i=0; i<a.length; i++) {
  a[i] = i;
  obj["obj" + i] = i;
}

Tests:

Array
r = Math.floor(Math.random()*n); for (var i=0; i<a.length; i++) { if (a[i] == r) break; }
Object
r = Math.floor(Math.random()*n); var i = obj["obj"+r];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array
Object

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 JSON and explain what's being tested.

**Benchmark Definition**

The benchmark definition defines two test cases:

1. "Array": This test case creates an array `a` with 5 elements, populates it with numbers from 0 to 4, and then searches for a random number `r` in the array using a loop.
2. "Object": This test case creates an object `obj` with 5 keys (e.g., "obj0", "obj1", ..., "obj4") and populates it with numbers from 0 to 4. It then searches for a random number `r` in the object using its key.

**Options compared**

The benchmark compares two approaches:

1. **Array search**: Searching for an element in an array using a loop.
2. **Object search**: Searching for a value in an object using its key.

**Pros and Cons of each approach:**

* **Array search**:
	+ Pros: Efficient use of memory, easy to implement.
	+ Cons: May be slower due to the need to iterate over all elements in the array.
* **Object search**:
	+ Pros: Can be faster for small objects (e.g., when the number of keys is close to the number of values), as it only needs to access a single value per iteration.
	+ Cons: May be slower for large objects, as accessing an object's key can lead to slower lookup times.

**Library and its purpose**

There is no explicit library mentioned in the benchmark definition. However, it's likely that the `for` loop and `var` declarations are part of the JavaScript standard library.

**Special JS feature or syntax (None)**

Since there are no special JavaScript features or syntax used in this benchmark, I won't mention anything about them.

**Other alternatives**

Some alternative approaches to search an array or object might include:

* **Using a data structure like a Set**: For arrays, Sets provide fast membership testing. For objects, Sets can be used as a key-value store.
* **Using a library like Lodash**: Lodash provides various utility functions, including those for array and object manipulation.

**Benchmark preparation code**

The script preparation code defines two variables: `n`, which is set to 5; `a`, an empty array with length 5; and `obj`, an empty object. The code then populates both arrays/object using a loop.

Note that this code can be optimized or modified for better performance, but the benchmarker's goal is to test the raw execution times of the two search approaches.

Related benchmarks:

Array vs object (version: 0)

Comparing performance of: Array vs Object

Created: 8 years ago by: Guest

Jump to the latest result

Array

Object

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):