give a function a type typescript code example

Example 1: types function typescript

interface Alternate_Syntax_4_Advanced {
    title: string;
    callback<T extends unknown[], R = unknown>(...args?: T): R;
}

Example 2: types function typescript

interface Better_still_safe_but_way_more_flexible_fix {
    title: string;
    callback: <T = unknown, R = unknown>(args?: T) => R;
}
interface Alternate_Syntax_4_Better_still_safe_but_way_more_flexible_fix {
    title: string;
    callback<T = unknown, R = unknown>(args?: T): R;
}