error TS2339: Property 'split' does not exist on type 'string | string[]'. Property 'split' does not exist on type 'string[]'
The type you are trying to invoke split
on is string|string[]
, which means that value may be either a string
or a string[]
, in order for TypeScript to be happy, BOTH types must have a split
method. If you are confident that it will always be a string, either update the definition (if possible) or cast to a string
before calling split
:
(<string>req.headers.authorization).split
or
(req.headers.authorization as string).split