<ul><li>In Angular 16+ and 19, the new functional input API using input.required<T>() is a powerful way to declare inputs in standalone and signal-based components.</li><li>The difference between characters = input.required<Character[]>(); and characters = input.required<Character[]>().signal is that the latter throws an error because the .signal accessor is not implemented in Angular 19.</li><li>The input.required<T>() function returns a required input and an InputSignal<T>, which can be used like a signal but is a distinct type.</li><li>Angular's input.required<T>() is already reactive and there is no need to use .signal to convert it.</li></ul>

Angular 16–19: Understanding `input.required()` vs `input.required().signal`

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