Undefined Packages

A small safe accessor that uses reduce to prevent 'Cannot read property of undefined' errors

Drops undefined arguments from the end of a function call.

returns a copy of an array or object with null/undefined members removed

Common types, type guards and type checkers.

Try to parse a string as JSON and return undefined on failure

parse argument options

Validates if a value is undefined or null.

util for validation that object has defined props

Check if something exists (e.g. not null || undefined)

checks if foo is not defined, i.e. undefined, null, an empty string, array, object or NaN

Check if the value is undefined, null, empty string, NaN and Infinity.

TypeScript recursive conversion between optional (partial) and undefined properties.

'cljs-merge' recursively merges two jsons into a unified one.

Determine type of property.

Clean objects recursively, deleting undefined & null or falsy properties

A typesafe way to get nested properties when any parent property might be undefined, while we wait for the optional chaining operator to finally exist

A Node.js library offering functions to check variable types, including arrays, objects, strings, numbers, booleans, and undefined values.

Library for handling possibly undefined values

Utilities for working with undefined properties

Tiny (220 bytes), zero dependency wrapper for nullable values