这里开始

int [][] array={{1,2,3,4},
{2,3,4,5,6},
{7,3,4,5,6}};
System.out.println(array.length);
System.out.println(array[0].length);
System.out.println(array[1].length);
System.out.println(array[2].length);
System.out.println(array[0][4]);

输出

3
4
5
5
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 4
at com.hui.study.Find.main(Find.java:19)