Benchmark: typeof 3 types using function

Tests:

isString
function isString(s){ return s && typeof o === 'string' } let s = ""; let is = isString(s);
isArray
function isArray(a){ return Array.isArray(a); } let arr = []; let is = isArray(arr);
isObject
function isObject(o){ o && typeof o === 'string' } let obj = {}; let is = isObject(obj);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
isString
isArray
isObject

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

Measuring JavaScript performance is crucial for optimizing code and ensuring compatibility across different browsers and environments.

**Benchmark Definition JSON Analysis**

The provided JSON represents a JavaScript microbenchmarking test case. Here's what it tests:

1. The `typeof` operator on various data types (string, array, object).
2. Three custom functions:
	* `isString(s)`: checks if the input string `s` is truthy and has a type of `'string'`.
	* `isArray(a)`: checks if the input `a` is an array using the `Array.isArray()` method.
	* `isObject(o)`: checks if the input `o` is truthy and has a type of `'string'`. **Note:** This function seems to have a logical error, as it will always return false for objects (since `typeof o` will evaluate to `'object', not `'string'`).**

**Options Compared in the Benchmark**

The benchmark compares three approaches:

1. Using the `typeof` operator with type checking.
2. Using the `Array.isArray()` method.
3. The custom `isObject(o)` function.

Each approach has its pros and cons:

* **`typeof` operator**: Pros: simple, widely supported, and efficient for most cases. Cons: may not work as expected for certain types (e.g., objects with `toString()` defined) or in older browsers that don't support it.
* **`Array.isArray()` method**: Pros: explicit, well-defined behavior, and generally supported by modern browsers. Cons: may be slower than the `typeof` operator for some cases.
* **Custom `isObject(o)` function**: Pros: none (seems to have a logical error). Cons: undefined behavior due to the incorrect type checking.

**Library Usage**

None of the custom functions (`isString`, `isArray`, and `isObject`) use any external libraries. However, it's worth noting that the `Array.isArray()` method is part of the standard JavaScript API.

**Special JS Features or Syntax**

There are no special JavaScript features or syntax used in this benchmark.

**Benchmark Preparation Code Analysis**

The provided script preparation code for each test case:

1. Defines a custom function (`isString(s)`, `isArray(a)`) and initializes variables (`s` and `arr`).
2. The `isObject(o)` function is defined with an incorrect type checking logic, which will always return false for objects.

**Latest Benchmark Result Analysis**

The latest benchmark results show:

1. Firefox 71 performs the best for `isString`, followed by `isArray`.
2. Firefox 71 also performs well for `isObject`, but due to its logical error, it's likely that other browsers or versions might behave differently.
3. The `isArray` function consistently outperforms both `typeof` operators.

**Other Alternatives**

For optimizing JavaScript performance and ensuring compatibility:

1. Use the `Array.isArray()` method instead of custom functions whenever possible.
2. Consider using libraries like `lodash` or `Ramda` for more advanced type checking and utility functions.
3. Test your code in multiple browsers and environments to ensure compatibility.
4. Profile and optimize hotspots in your code to identify performance bottlenecks.

By analyzing the benchmark definition, individual test cases, and latest results, developers can gain insights into the performance characteristics of different approaches and make informed decisions about their own JavaScript optimization strategies.

Related benchmarks:

typeof 3 types using function (version: 1)

typeof operator on various types

Comparing performance of: isString vs isArray vs isObject

Created: 6 years ago by: Registered User

Jump to the latest result

isString

isArray

isObject

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):