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Compare typeof vs null check 2
(version: 0)
Comparing performance of:
Is number vs Is null
Created:
2 years ago
by:
Guest
Go to the latest result
Script Preparation code:
const value = null
Tests:
Is number
const value = null return typeof value === 'string'
Is null
const value = null return value == null
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
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Test case name
Result
Is number
Is null
Fastest:
N/A
Slowest:
N/A
Latest run results:
Run details:
(Test run date:
one year ago
)
User agent:
Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Mobile Safari/537.36
Browser/OS:
Chrome Mobile 126 on Android
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<iframe src="https://measurethat.net/Embed?id=552318" width="100%" height="500px"></iframe>
Is number
18.0M/s
Is null
16.4M/s
View exact numbers
Test name
Executions per second
✓
Is number
17,957,674 Ops/sec
Is null
16,449,643 Ops/sec
Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's break down the benchmark and explain what's being tested. **Benchmark Overview** The benchmark is designed to compare two approaches for checking if a variable is `null` or not in JavaScript: 1. Using the `typeof` operator with a string comparison (`typeof value === 'string'`) 2. Using the `==` (double equals) operator for a loose equality check (`value == null`) **Options Compared** The benchmark compares two options for checking if a variable is `null` or not: Option 1: `typeof value === 'string'` This approach uses the `typeof` operator to get the type of the variable, and then checks if it's equal to `'string'`. This will return true for any object that has a `toString()` method, including non-string values. This is because `typeof` returns one of six strings (`"number"`, `"object"`, `"boolean"`, `"function"`, `"string"`, or `"undefined"`), and the comparison with `'string'` will match any value that's not `null`. Option 2: `value == null` This approach uses a loose equality check using the `==` operator. This will return true only if the variable is exactly equal to the value `null`. If the variable is an object or a non-numeric value, this comparison will be false. **Pros and Cons of Each Approach** Option 1: `typeof value === 'string'` Pros: * More robust for checking non-string values (e.g., objects, functions) * Less prone to typos or unexpected behavior Cons: * May return true for non-`null` values that have a `toString()` method * Can be slower due to the additional step of getting the type Option 2: `value == null` Pros: * Faster and more lightweight compared to Option 1 * Returns true only when the variable is exactly equal to `null` Cons: * May return false for non-`null` values (e.g., objects, functions) * Prone to typos or unexpected behavior if not used carefully **Library Usage** In this benchmark, no library is explicitly mentioned. However, it's worth noting that the use of `typeof` relies on the JavaScript engine's implementation of the `toString()` method. **Special JS Features/Syntax** There are no special JS features or syntax mentioned in this benchmark. **Other Alternatives** Alternative approaches for checking if a variable is `null` or not include: 1. Using the `===` operator with an explicit comparison to `null` (`value === null`) 2. Using the `instanceof` operator, which can be used to check if an object is an instance of a specific constructor (e.g., `value instanceof Null`) However, these alternatives are not part of this benchmark, and their performance may vary depending on the JavaScript engine and browser. Overall, the benchmark provides a useful comparison between two common approaches for checking if a variable is `null` or not in JavaScript.
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