数组中常见的异常
- 数组角标越界的异常：ArrayIndexOutOfBoundsExcetion
- 空指针异常：NullPointerException
空指针异常
情况1
int[] arr1 = new int[]{1, 2, 3};
arr1 = null;
System.out.println(arr1[0]);
情况2
int[][] arr2 = new int[4][];
System.out.println(arr2[0][0]);
情况3，对象是一个null
String[] arr3 = new String[]{"aa", "bb", "cc"};
arr3[0] = null;
System.out.println(arr3[0].toString());
