Benchmark: Array: findIndex vs forEach

Script Preparation code:

var arr = []
for (let i=1;i < 15001; i++) {
  arr.push({a:i,b:i*2,c:i*3})
}
var match_a = 11111, match_b = 22222, match_c = 33333;

Tests:

forEach
arr.forEach( (v,i,a) => { if (v.a===match_a,v.b===match_b,v.c===match_c) { return i } } )
findIndex
arr.findIndex( (v,i,a) => { if(v.a===match_a,v.b===match_b,v.c===match_c) { return i } } )

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
forEach
findIndex

Fastest: N/A

Slowest: N/A

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

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Let's break down the provided JSON and benchmark results.

**Benchmark Definition**

The provided JSON represents a JavaScript microbenchmark test case named "Array: findIndex vs forEach". The test case measures the performance difference between using `Array.prototype.findIndex()` and `Array.prototype.forEach()` to find an element in an array that matches certain conditions.

The script preparation code creates an array of 15,001 elements with properties `a`, `b`, and `c`. Three match values (`match_a`, `match_b`, and `match_c`) are defined. The test case requires finding the index of each match value in the array.

**Comparison Options**

There are two comparison options:

1. **forEach**: This approach uses `Array.prototype.forEach()` to iterate over the array, checking each element's properties against the match values. If a match is found, the function returns the current index.
2. **findIndex**: This approach uses `Array.prototype.findIndex()` to find an index that satisfies the condition (i.e., when the element's property matches one of the specified values).

**Pros and Cons**

* **forEach**:
	+ Pros: Can return early as soon as a match is found, which might improve performance in cases where the array is large but only some elements match.
	+ Cons: Returns `undefined` if no match is found, which can lead to unnecessary iterations. Also, it has side effects ( modifies the original array) and may not be suitable for all use cases.
* **findIndex**:
	+ Pros: More straightforward and efficient than `forEach`. Returns `-1` when no element matches.
	+ Cons: May iterate over the entire array if no match is found, leading to potential performance issues. Also, it has side effects (modifies the original array) and may not be suitable for all use cases.

**Library Usage**

In both test cases, the `Array.prototype.forEach()` and `Array.prototype.findIndex()` methods are used without any additional libraries. These are built-in JavaScript methods that operate on arrays.

**Special JS Features or Syntax**

The benchmark uses regular expressions (`\tif` is not a valid regex syntax in JavaScript; I assume it's a typo) within string templates (e.g., `\r\n\t(v,i,a) => {\r\n\t\tif (v.a===match_a,v.b===match_b,v.c===match_c) {\r\n\t\t\treturn i \r\n\t\t}`). This is valid JavaScript syntax, using template literals to create a function expression.

**Other Alternatives**

If you need to find an element in an array based on certain conditions, other alternatives include:

* Using `Array.prototype.every()` or `Array.prototype.some()`, which return a boolean value indicating whether at least one element satisfies the condition.
* Creating a custom iterator or using a library like Lodash's `findIndexBy` function.
* Using a different data structure, such as an object with array-like properties (e.g., `Object.keys()`).

In summary, the "Array: findIndex vs forEach" benchmark test case measures the performance difference between two common methods for finding elements in arrays that match certain conditions. Understanding the pros and cons of each approach can help you choose the most suitable method for your specific use case.

Related benchmarks:

Array: findIndex vs forEach (version: 0)

Finds out which performs better. Getting index according after satisfying requirement.

Comparing performance of: forEach vs findIndex

Created: 4 years ago by: Guest

Jump to the latest result

forEach

findIndex

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):