typescript optional parameter without ? code example
Example 1: How to pass optional parameters while omitting some other optional parameters?
export interface INotificationService {
error(message: string, title?: string, autoHideAfter? : number);
}
class X {
error(message: string, title?: string, autoHideAfter?: number) {
console.log(message, title, autoHideAfter);
}
}
new X().error("hi there", undefined, 1000);
Example 2: typescript make function argument optional
function multiply(a: number, b: number, c?: number): number {
if (typeof c !== 'undefined') {
return a * b * c;
}
return a * b;
}