Benchmark: isString Test - MeasureThat.net

HTML Preparation code:


<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

function isString(input) {
    if (input === '') return true;

    if (input && typeof input.valueOf() === 'string') {
        return true;
    }

    return false;
}

var emptyString = '';
var nullString = null;
var normalString = 'hello';
var array = ['hello'];
var otherObject = {};
var objectString = new String('hello');

Tests:

lodash
for (let i = 0; i < 1000; i++) { _.isString(emptyString); _.isString(nullString); _.isString(normalString); _.isString(array); _.isString(otherObject); _.isString(objectString); }
replacement
for (let i = 0; i < 1000; i++) { isString(emptyString); isString(nullString); isString(normalString); isString(array); isString(otherObject); isString(objectString); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash
replacement

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
lodash	12070.0 Ops/sec
replacement	43333.5 Ops/sec

Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data and explain what's being tested.

**Benchmark Definition**

The benchmark is called "isString Test" and has two test cases: "lodash" and "replacement". The script preparation code defines a function `isString` that takes an input and returns a boolean indicating whether it's a string. The function uses a few special variables:

* `emptyString`: an empty string
* `nullString`: a null value (not a string)
* `normalString`: a string containing the text "hello"
* `array`: an array containing a single string element ("hello")
* `otherObject`: an object (not a string)
* `objectString`: a string created using the String constructor

The HTML preparation code loads the Lodash library from a CDN.

**Test Cases**

There are two test cases:

1. **Lodash**: This test case uses the Lodash library to call the `isString` function for each of the special variables defined above. The benchmark definition is a JavaScript loop that calls `_isString()` (a method provided by Lodash) 1000 times with each variable as input.
2. **Replacement**: This test case does not use any external libraries and instead uses the plain `isString` function defined in the script preparation code to call itself for each of the special variables, just like in the Lodash test case.

**Latest Benchmark Result**

The latest benchmark result shows two rows:

* For the "replacement" test case (i.e., calling the `isString` function without any library), Chrome 95 can execute the test 1303.593994140625 times per second.
* For the "lodash" test case (i.e., using Lodash's `_isString()` method), Chrome 95 can execute the test 817.396240234375 times per second, which is slower than the replacement version.

**What's being tested?**

The benchmark tests the performance of two approaches to checking if a value is a string:

1. **Lodash**: Using a popular JavaScript library (Lodash) that provides an `isString` method.
2. **Replacement**: Calling a custom `isString` function defined in plain JavaScript.

**Pros and Cons:**

* Lodash:
	+ Pros: Provides a widely used, well-maintained library with many other utility functions.
	+ Cons: Adds extra overhead due to the library's loading time and method invocation.
* Replacement:
	+ Pros: No external dependencies, potentially faster execution due to lower overhead.
	+ Cons: Requires developers to implement custom logic for each utility function they need.

**Other Alternatives**

Other alternatives for checking if a value is a string in JavaScript include:

1. **Built-in `typeof` operator**: Using the `typeof` operator with the string operand (`"hello".typeof === "string"`).
2. **JavaScript's native `String.prototype.toString()` method**: Calling `toString()` on a value to convert it to a string (e.g., `"hello".toString()`).

These alternatives are not explicitly tested in this benchmark, but they might be relevant for other use cases.

Hope this explanation helps!

Related benchmarks:

isString Test (version: 0)

Comparing performance of: lodash vs replacement

Created: 5 years ago by: Registered User

Jump to the latest result

lodash

replacement

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):