Javascript check for undefined or null object/variable
By Valerie Conn at May 13 2022
javascript syntax for check null or undefined or empty
By Bobby Cummings at Aug 28 2020
javascript check if undefined or null or empty string
By Rose Harvey at May 01 2020
TypeError: ShallowWrapper::state requires that `state` not be `null` or `undefined`
By Sudarshaana at Feb 29 2020