96 lines
3.4 KiB
Markdown
96 lines
3.4 KiB
Markdown
# boolean
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boolean converts lots of things to boolean.
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## Status
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| Category | Status |
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| ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------ |
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| Version | [](https://www.npmjs.com/package/boolean) |
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| Dependencies |  |
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| Dev dependencies |  |
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| Build |  |
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| License |  |
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## Installation
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```shell
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$ npm install boolean
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```
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## Quick start
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First you need to add a reference to boolean in your application:
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```javascript
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const { boolean, isBooleanable } = require('boolean');
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```
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If you use TypeScript, use the following code instead:
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```typescript
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import { boolean, isBooleanable } from 'boolean';
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```
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To verify a value for its boolean value, call the `boolean` function and provide the value in question as parameter:
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```javascript
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console.log(boolean('true')); // => true
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```
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The `boolean` function considers the following values to be equivalent to `true`:
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- `true` (boolean)
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- `'true'` (string)
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- `'TRUE'` (string)
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- `'t'` (string)
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- `'T'` (string)
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- `'yes'` (string)
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- `'YES'` (string)
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- `'y'` (string)
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- `'Y'` (string)
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- `'on'` (string)
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- `'ON'` (string)
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- `'1'` (string)
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- `1` (number)
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In addition to the primitive types mentioned above, boolean also supports their object wrappers `Boolean`, `String`, and `Number`.
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_Please note that if you provide a `string` or a `String` object, it will be trimmed._
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All other values, including `undefined` and `null` are considered to be `false`.
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### Figuring out whether a value can be considered to be boolean
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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`).
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To figure out whether a value can be considered to be a boolean, use the `isBooleanable` function:
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```javascript
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console.log(isBooleanable('true')); // => true
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```
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The `isBooleanable` function considers all of the above mentioned values to be reasonable boolean values, and additionally, also the following ones:
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- `false` (boolean)
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- `'false'` (string)
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- `'FALSE'` (string)
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- `'f'` (string)
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- `'F'` (string)
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- `'no'` (string)
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- `'NO'` (string)
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- `'n'` (string)
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- `'N'` (string)
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- `'off'` (string)
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- `'OFF'` (string)
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- `'0'` (string)
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- `0` (number)
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## Running quality assurance
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To run quality assurance for this module use [roboter](https://www.npmjs.com/package/roboter):
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```shell
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$ npx roboter
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```
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