3.4 KiB
boolean
boolean converts lots of things to boolean.
Status
| Category | Status |
|---|---|
| Version |  |
| Dependencies |  |
| Dev dependencies |  |
| Build |  |
| License |  |
Installation
$ npm install boolean
Quick start
First you need to add a reference to boolean in your application:
const { boolean, isBooleanable } = require('boolean');
If you use TypeScript, use the following code instead:
import { boolean, isBooleanable } from 'boolean';
To verify a value for its boolean value, call the boolean function and provide the value in question as parameter:
console.log(boolean('true')); // => true
The boolean function considers the following values to be equivalent to true:
true(boolean)'true'(string)'TRUE'(string)'t'(string)'T'(string)'yes'(string)'YES'(string)'y'(string)'Y'(string)'on'(string)'ON'(string)'1'(string)1(number)
In addition to the primitive types mentioned above, boolean also supports their object wrappers Boolean, String, and Number.
Please note that if you provide a string or a String object, it will be trimmed.
All other values, including undefined and null are considered to be false.
Figuring out whether a value can be considered to be boolean
From time to time, you may not want to directly convert a value to its boolean equivalent, but explicitly check whether it looks like a boolean. E.g., although boolean('F') returns false, the string F at least looks like a boolean, in contrast to something such as 123 (for which boolean(123) would also return false).
To figure out whether a value can be considered to be a boolean, use the isBooleanable function:
console.log(isBooleanable('true')); // => true
The isBooleanable function considers all of the above mentioned values to be reasonable boolean values, and additionally, also the following ones:
false(boolean)'false'(string)'FALSE'(string)'f'(string)'F'(string)'no'(string)'NO'(string)'n'(string)'N'(string)'off'(string)'OFF'(string)'0'(string)0(number)
Running quality assurance
To run quality assurance for this module use roboter:
$ npx roboter