Application to find leap years, create leap year list, non-leap year list, find number of leap years in a range. Year with 4 digits or less.Can be used in reactive and mobile app.

This component checks if it only has letters and returns a true boolean or if it has another type of character and returns false. Esse componente verifica se apenas tem letras e devolve um boolean verdadeiro ou se tem outro tipo de caracter e devolve false