java throw throws

结论：

①throw+ an instance of Exception Class

②throws+ Exception Class

举例:

①throw+ an instance of Exception Class

throw new ArithmeticException("Arithmetic Exception");

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Example2020.java

public class Example2020 {
    void checkAge(int age) {
        if (age < 18)
            throw new ArithmeticException("you are not an adult");
        else
            System.out.println("you are an adult");
    }

    public static void main(String[] args) {
        Example2020 obj = new Example2020();
        obj.checkAge(12);
        System.out.println("End.");
    }

}

②throws+ Exception Class

throws ArithmeticException;

public class Example2021 {
    int division(int a, int b) throws ArithmeticException {
        int t = a / b;
        return t;
    }

    public static void main(String[] args) {
        Example2021 obj = new Example2021();
        try {
            System.out.println(obj.division(12, 0));

        } catch (ArithmeticException e) {
            System.out.println("you should not divide number by zero");
        }
    }

}