package java_test;

public class Array_test {
    public static void main(String[] args){
        int [][] a= {{1,2,3},{2,3,4,5},{17,18,19,20,99,87}};
        System.out.println("数组a的行数为"+a.length);//求数组的行数
        for(int i =0;i<a.length;i++){
            System.out.println("第"+(i+1)+"行列数为"+a[i].length);//求数组每行有多少列
        }
        
    }
}