Safely get a dot-notated path within a nested object, with ability to return a default if the full key path does not exist or the value is undefined
Smallest possible implementation: only 120 bytes.
You could write this yourself, but then you'd have to write tests.
Supports ES Modules, CommonJS and globals.
npm install --save dlv
delve(object, keypath, [default])
import delve from 'dlv'; let obj = { a: { b: { c: 1, d: undefined, e: null } } }; //use string dot notation for keys delve(obj, 'a.b.c') === 1; //or use an array key delve(obj, ['a', 'b', 'c']) === 1; delve(obj, 'a.b') === obj.a.b; //returns undefined if the full key path does not exist and no default is specified delve(obj, 'a.b.f') === undefined; //optional third parameter for default if the full key in path is missing delve(obj, 'a.b.f', 'foo') === 'foo'; //or if the key exists but the value is undefined delve(obj, 'a.b.d', 'foo') === 'foo'; //Non-truthy defined values are still returned if they exist at the full keypath delve(obj, 'a.b.e', 'foo') === null; //undefined obj or key returns undefined, unless a default is supplied delve(undefined, 'a.b.c') === undefined; delve(undefined, 'a.b.c', 'foo') === 'foo'; delve(obj, undefined, 'foo') === 'foo';