java实践（七）——异常类

实践目的

1.了解异常的概念

2.掌握异常的抛出和捕获

3.了解自定义异常类

 

实践内容

1.抛出与捕获异常

public class Chap2_4_2 
{
	public static void main(String[] args) 
	{
		Student s1 = new Student();
		
		try{
			System.out.println(s1.age/0);
		}
		catch(Exception e)//捕获异常
		{
			System.out.println(e.toString());//输出异常
		}

		System.out.println("Hello World!");
	}
}

class Student
{
	public String name;
	public int age;

	//public void reset() throw Exception
	//{
	//	age = 1/0;
	//	name = "";
	//}
}

总结

 1.常见的异常类

    NullPointerException

    ArithmeticException

   IndexOutOfBoundsException

2.捕获异常的程序结构

try{

}catch (){

}

finally{

}