runtimeexception_ex.java

《Java2程序设计实用教程(第2版)》课件

public class RuntimeException_ex
{
    public static void main(String args[]) 
    {
        int a[] = null;
        a[0] = 0;                           //空对象异常NullPointerException
        
        String str = null;
        System.out.println(str.length());   //空对象异常NullPointerException
        
        int b[] = new int [-1];             //负数组长度异常NegativeArraySizeException
        
        Object obj = new Object();
        String str = (String) obj;          //类型强制转换异常ClassCastException

    }
}