void = function don’t return value.
any = function return something (not recommended).
optional parameter = ?
function objectParam(num: number, b?: string): boolean {
return num % 2 === 0
}
dual parameter + cast
function dualParam(num: number | string): boolean {
if (typeof num !== 'number') {
num = parseInt(num, 10);
}
return <number>num % 2 === 0
}
Enum
enum UserResponse {
No = 0,
Yes = 1,
}
function respond(recipient: string, message: UserResponse): void {
// ...
}
respond("Princess Caroline", UserResponse.Yes);