Can you explain the meanings of ? and | in a function definition like the one below?
export function readFileSync(path: PathLike | number, options: { encoding: BufferEncoding; flag?: string; } | BufferEncoding): string;
Appreciate your help,
Can you explain the meanings of ? and | in a function definition like the one below?
export function readFileSync(path: PathLike | number, options: { encoding: BufferEncoding; flag?: string; } | BufferEncoding): string;
Appreciate your help,
The symbol ? represents an optional property.
In certain cases, not all properties included in an interface are mandatory. Some are conditional or may not be present at all. Optional properties are commonly used when creating structures like "option bags," where only a few properties are filled in when passing an object to a function.
The symbol | serves as the union type operator. It functions similarly to an "or" operator by indicating that the type has multiple options that can fulfill it.
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