Angular / Typescript interview questions
What does the question mark (?) on a typescript variable/parameter name denote?
Question mark on a typescript variable marks it as optional. Any optional parameters must follow required parameters.
function sayHello(name: string, salutation?: string) { if (salutation) return "Hello " + saluation +"." + name; else return "Hello " + name; }
The optional parameters will have value as undefined
when unused.
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