The request.query object is of type ParsedQs, which is defined as:
interface ParsedQs {
[key: string]: undefined
| string
| string[]
| ParsedQs
| ParsedQs[]
}
My interpretation of each type is as follows:
A value is
undefinedwhen it is not present in the parameters.
For example: accessingrequest.query.bwhen the parameters are?a=1.A value is a
stringwhen it appears once in the parameters. For example: accessingrequest.query.awhen the parameters are?a=1.A value is a
string[]when it appears multiple times in the parameters. For example: accessingrequest.query.awhen the parameters are?a=1&a=2.
But when is a value considered a ParsedQs itself?