typechecker

TypeChecker

Utilities to get and check variable types (isString, isPlainObject, isRegExp, etc)

Install

Backend

1. Install Node.js
2. npm install --save typechecker

Frontend

1. See Browserify

Usage

Example

require('typechecker').isRegExp(/^a/)  // returns true

Methods

• getObjectType - returns the object string of the value, e.g. when passed /^a/ it'll return "[object RegExp]"
• getType - returns lower case string of the type, e.g. when passed /^a/ it'll return "regex"
• isPlainObject - returns true if the value doesn't have a custom prototype
• isError - returns true if the value an error, otherwise false
• isDate - returns true if the value is a date, otherwise false
• isArguments - returns true if the value is function arguments, otherwise false
• isFunction - returns true if the value is a function, otherwise false
• isRegExp - returns true if the value is a regular expression instance, otherwise false
• isArray - returns true if the value is an array, otherwise false
• isNumber - returns true if the value is a number ("2" is a string), otherwise false
• isString - returns true if the value is a string, otherwise false
• isBoolean - returns true if the value is a boolean, otherwise false
• isNull - returns true if the value is null, otherwise false
• isUndefined - returns true if the value is undefined, otherwise false
• isEmpty - returns true if the value is null or undefined
• isEmptyObject - returns true if the object has no keys that are its own

Notes

Why should I use this instead of say instanceof? Under certain circumstances instanceof may not return the correct results. This occurs with node's vm module especially, and circumstances where an object's prototype has been dereferenced from the original. As such, for basic == and === checks (like a === null), you're fine not using this, but for checks when you would have done instanceof (like err instanceof Error), you should try to use this instead. Plus things like isEmptyObject and isPlainObject are darn useful!

History

You can discover the history inside the History.md file

License

Licensed under the incredibly permissive MIT License
Copyright © 2013+ Bevry Pty Ltd
Copyright © 2011-2012 Benjamin Arthur Lupton