Undefined Packages

ECMAScript “ToPrimitive” algorithm. Provides ES5 and ES2015 versions.

Undefined safe way of extracting object properties

return the first argument that is `!== undefined`

Coalesce for JavaScript. Returns the first value that is not undefined or null.

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

Returns true if the given is falsey (according to JavaScript) or matches a 'falsey' keyword.

Simple function that return the first non null or undefined argument

Checks if the given value is null or undefined

Safe Window Getters

Validates if a value is undefined.

coffeelint plugin that handles variables and their scope

A library to have a generic typescript definition for object presence.

Check if a value is undefined or not.

Recursively remove deeply nested properties and/or falsey values (excluding 0), empty objects, and empty arrays.

Check for a valid Number value.

Validate the type of object's properties.

Ensures value is defined (i.e., neither undefined nor null).

Remove undefined properties from object

Improved type check

exists and allExist functions. plain and simple