Parameters constructs a tuple type from the types used in the parameters of a function type Type.
type T0 = Parameters<() => string>;
// type T0 = []
type T1 = Parameters<(s: string) => void>;
// type T1 = [s: string]
type T2 = Parameters<<T>(arg: T) => T>;
// type T2 = [arg: unknown]
declare function f1(arg: { a: number; b: string }): void;
type T3 = Parameters<typeof f1>;
// type T3 = [arg: {
// a: number;
// b: string;
// }]
type T4 = Parameters<any>;
// type T4 = unknown[]
type T5 = Parameters<never>;
// type T5 = never
type T6 = Parameters<string>;
// ^ Type 'string' does not satisfy the constraint '(...args: any) => any'.
type T7 = Parameters<Function>;
// ^ Type 'Function' does not satisfy the constraint '(...args: any) => any'.Learn more from the following links: