Lately, I've come across code snippets similar to the following:
export interface IUser {
email?: string;
firstName?: string;
lastName?: string;
}
I've found myself wondering, why do the variable names have a question mark at the end? This snippet is from an example involving mongodb and Typescript.
The answer must be out there somewhere, but it seems like my search terms are not quite hitting the mark.
Within TypeScript, utilizing <name>?: <typename> serves as a condensed version of
<name>: <typename> | undefinedThis informs the type system that a symbol may hold a value of the specified type or it may be assigned the value undefined (similar to null).
Understanding this becomes crucial when making use of the --strictNullChecks feature introduced in TypeScript 2. Referencing the documentation on Null- and undefined-aware types is highly recommended for further clarification.
This feature offers the flexibility for presence without obligation. It facilitates the inclusion of optional field labels, a frequently utilized functionality.
For instance, it can be applied to enable users on a platform to input an optional display name.
As far as I know, the purpose of this marker is to signify that it's not mandatory, suggesting that it may be left blank.
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