Arrays - A Concise and Practical Introduction to Programming Algorithms in Java - page 95

int [] z= MultiplyMatrixVector (M,v) ;

for ( int i=0;i < z . length ; i++)
System . out . print ( z [ i ]+ "" );

}

}

Thus it is quite easy to write basic functions of linear algebra . Note that in Java,
it is not necessary 6 to provide the function with the array dimensions since we
can retrieve these dimensions with the length keyword, as shown below:

Program 4.12 Creating multidimensional arrays and retrieving their

dimensions
class MultidimArrays
static void f2D( double [] [] tab)
{ System . out . println ( "Number of lines:" +tab . l e n g t h ) ;
System . out . println ( "Number of columns:" +tab[0]. length);
static void f3D( double [] [] [] tab)
{ System . out . println ( "Number of lines X:" +tab . l e n g t h ) ;
System . out . println ( "Number of columns Y:" +tab [0]. length) ;
System . out . println ( "Number of depths Z:" +tab[0][0]. length);
} public static void main( String [ ]

args )

{ double []

[] var= new double [3][4];

f2D( var ) ;
double [] [] [] tmp= new double [4][5][7];

f3D(tmp) ;

}
}

Running this program, we see that we correctly retrieved the 2D and 3D array
dimensions given as function arguments:
Number of lines:3
Number of columns:4
Number of lines X:4
Number of columns Y:5
Number of depths Z:7

4.5.2 Multi-dimensional ragged arrays **

Multi-dimensional arrays need not be regular: They can be completely irregular.
That is, a multi-dimensional array can also be defined as a 1D array of arrays,
6 In the C programming language, one has to pass these dimensions as arguments.