how to pass optional parameter in typescript code example
Example 1: typescript optional parameters
sayHello(hello: string = 'hello') {
console.log(hello);
}
sayHello();
sayHello('world');
Example 2: how to make a parameter optional in typescript
function foo(x?: number) {
console.log("x : "+ x);
}
foo();
foo(6);
Example 3: 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);