How to assign string | undefined to string in TypeScript?
The typescript compiler performs strict null checks, which means you can't pass a string | undefined
variable into a method that expects a string
.
To fix this you have to perform an explicit check for undefined
before calling luminaireReplaceLuminaire()
.
In your example:
private selectedSerialForReplace(): string | undefined {
return this.selectedSerials.pop();
}
luminaireReplaceLuminaire(params: { "serial": string; "newserial": string; }, options?: any): FetchArgs {
............
}
const serial = this.selectedSerialForReplace();
if(serial !== undefined) {
luminaireReplaceLuminaire({serial, newserial: response.output});
}
If you are sure that serial could not be undefined
you can use the !
post-fix operator
luminaireReplaceLuminaire({serial: this.selectedSerialForReplace()!, newserial: response.output});