Java二维数组实战案例

int [][] num={
  {1,2,3,4},
  {1,2,3},
  {1,2,3,4,5}
 };

int [][] num =null;
num = new int[3][];
num[0] = new int[4];
num[1] = new int[3];
num[2] = new int[5];

int len,len0,len1,len2;
len = num.length;      // 计算num的行数
len0 = num[0].length;    // 计算num第1行元素的个数
len1 = num[1].length;    // 计算num第2行元素的个数
len2 = num[2].length;    // 计算num第3行元素的个数

public class twoDimensionArray
{
   public static void main( String[] args )
   {
      int sum = 0;
      int[][] num = {
           { 30, 35, 26, 32 },
           { 33, 34, 30, 29 }
           };             // 声明数组并设置初值
      for( int i = 0; i < num.length; ++i )      // 输出销售量并计算总销售量
      {
      System.out.print( "第 " + (i + 1) + " 个人的成绩为：" );
      
      for( int j = 0; j < num[i].length ; ++j )
      {
         System.out.print( num[ i ][ j ] + " " );
         sum += num[ i ][ j ];
      }
        System.out.println();
      }
      System.out.println( "\n总成绩是 " + sum + " 分！" );
   }
}