4、编写2个接口：InterfaceA和InterfaceB；在接口InterfaceA中有个方法voidprintCapitalLetter()；在接口InterfaceB中有个方法void printLowercaseLetter()；然后写一个类Print实现接InterfaceA和InterfaceB，要求printCapitalLetter()方法实现输出大写英文字母表的功能，printLowercaseLetter()方法实现输出小写英文字母表的功能。再写一个主类E，在主类E的main方法中创建Print的对象并赋值给InterfaceA的变量a，对象a调用printCapitalLetter方法；最后再在主类E的main方法中创建Print的对象并赋值给InterfaceB的变量b，对象b调用printLowercaseLetter方法这个是Java程序

InterfaceA.java:

public interface InterfaceA {
    void printCapitalLetter();
}

InterfaceB.java:

public interface InterfaceB {
    void printLowercaseLetter();
}

Print.java:

public class Print implements InterfaceA, InterfaceB {
    @Override
    public void printCapitalLetter() {
        for (char c = 'A'; c <= 'Z'; c++) {
            System.out.print(c + " ");
        }
        System.out.println();
    }

    @Override
    public void printLowercaseLetter() {
        for (char c = 'a'; c <= 'z'; c++) {
            System.out.print(c + " ");
        }
        System.out.println();
    }
}

E.java:

public class E {
    public static void main(String[] args) {
        InterfaceA a = new Print();
        a.printCapitalLetter();

        InterfaceB b = new Print();
        b.printLowercaseLetter();
    }
}

输出结果：

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 
a b c d e f g h i j k l m n o p q r s t u v w x y z