java-異常-原理異常物件的丟擲throw
阿新 • • 發佈:2021-11-03
1 class Demo { 2 public static int method(int[] arr,int index) { 3 4 // System.out.println(arr[index]); 5 if (arr == null) { 6 throw new NullPointerException("陣列的引用不能為空"); 7 } 8 if (index>=arr.length) { 9 throw new ArrayIndexOutOfBoundsException("陣列的角標越界"+index);ExceptionDemo210 11 } 12 if (index<0) { 13 throw new ArrayIndexOutOfBoundsException("陣列的角標不能為負數"+index); 14 } 15 return arr[index]; 16 } 17 18 } 19 20 public class ExceptionDemo2 { 21 22 public static void main(String[] args) { 23 // TODO Auto-generated method stub24 int[] arr = new int[3]; 25 // System.out.println(arr[3]); 26 27 Demo d = new Demo(); 28 int num = d.method(null,-30); 29 System.out.println("num="+num); 30 System.out.println("over"); 31 32 } 33 34 }