JAva 2 D配列を定義するいくつかの書き方

class numthree
{
public static void main(String[] args)
{
float[][] numthree;             //    float   2   
numthree=new float[5][5];       //    5 5      
numthree[0][0]=1.1f;            //              1 1 =1.1
numthree[1][0]=1.2f;                                  // 2 1 =1.2
numthree[2][0]=1.3f;                                  // 3 1 =1.3
numthree[3][0]=1.4f;                                  // 4 1 =1.4
numthree[4][0]=1.5f;                                  // 5 1 =1.5
System.out.println(numthree[0][0]); //        
System.out.println(numthree[1][0]);
System.out.println(numthree[2][0]);
System.out.println(numthree[3][0]);
System.out.println(numthree[4][0]);
}
}

//        2              
class numfour
{
public static void main(String[] args)
{
   short[][] numfour=new short[5][8]; //    short           5 8      
   numfour[0][7]=10;
   numfour[1][6]=20;
   numfour[2][5]=30;
   numfour[3][4]=40;
   numfour[4][3]=50;
   System.out.println(numfour[0][7]);
   System.out.println(numfour[1][6]);
   System.out.println(numfour[2][5]);
   System.out.println(numfour[3][4]);
   System.out.println(numfour[4][3]);
}
}


//        3             
class numfive
{
public static void main(String[] args)
{
long[][] numfive=new long[5][];     //    long         
numfive[0]=new long[5];             //  1   5 
numfive[1]=new long[6];             //  2   6 
numfive[2]=new long[7];             //  3   7 
numfive[3]=new long[8];             //  4   8 
numfive[4]=new long[9];             //  5   9 

numfive[0][4]=10000000000L;         //1 5 =10000000000
numfive[1][5]=20000000000L;         //2 6 =20000000000
numfive[2][6]=30000000000L;         //3 7 =30000000000
numfive[3][7]=40000000000L;         //4 8 =40000000000
numfive[4][8]=50000000000L;         //5 9 =50000000000

System.out.println(numfive[0][4]); //        
System.out.println(numfive[1][5]);
System.out.println(numfive[2][6]);
System.out.println(numfive[3][7]);
System.out.println(numfive[4][8]);
System.out.println(numfive[4][7]); //                  java          0
}
}


//  2     4             
class numsix
{
public static void main(String[] args)
{
double[][] numsix={{1.111D,2.222D,3.333D},{4.444D,5.555D,6.666D}};//  double      3 3        
System.out.println(numsix[0][0]); //      1 1 =1.111
System.out.println(numsix[1][1]); //      2 2 =5.555
}
}


//  2     5         2         
class numseven
{
public static void main(String[] args)
{
int[][] numseven=new int[][]{{10,20,30},{40,50},{60}}; //                   ！
System.out.println(numseven[0][2]);
System.out.println(numseven[1][1]);
System.out.println(numseven[0][0]);
}
}

//  2     6       2         ；
class numeight
{
public static void main(String[] args)
{
int[][] numeight={{100,200,300,400},{500,600,700,800},{900,1000,1100,1200,1300}};
System.out.println(numeight[0][2]);
System.out.println(numeight[1][2]);
System.out.println(numeight[2][1]);
}
}