Skip to content

Multi-Dimensional Arrays

Any of the single dimension array types listed above can be used to define an array of n-dimensions. A 2-dimensional array is simply a collection of 1-dimensional arrays; a 3-dimensional array is a collection of 2-dimensional arrays, and so forth.

Example

1
2
3
INTEGER Num1D[10]  // [Column]
INTEGER Num2D[5][10]  // [Row][Column]
INTEGER Num3D[2][5][10] // [Table][Row][Column]

One way to view these arrays is to think of Num2D as being a collection of five Num1D's and Num3D as being a collection of two Num2D's.

When referencing elements of the above arrays…

1
2
3
4
5
6
Num1D[1]    // refers to the 1st element
Num2D[1]    // refers to the 1st row
Num2D[1][1] // refers to the 1st element of the 1st row
Num3D[1]    // refers to the 1st table
Num3D[1][1]     // refers to the 1st row of the 1st table
Num3D[1][1][1]  // refers to the 1st element of the 1st row of the 1st table

The following operations are legal:

1
2
3
4
5
Num2D[2] = Num1D
Num2D[5][5] = Num1D[5]
Num3D[2] = Num2D
Num3D[2][1] = Num1D
Num3D[2][1][1] = Num1D[1]

LENGTH_ARRAY and MAX_LENGTH_ARRAY are used to determine the effective and maximum lengths of multidimensional arrays as shown in the following examples.

Example 1

1
2
3
4
5
INTEGER Len INTEGER My3DArray[5][3][4]

Len = MAX_LENGTH_ARRAY(My3Darray) // Len = 5
Len = MAX_LENGTH_ARRAY(My3Darray[1]) // Len = 3
Len = MAX_LENGTH_ARRAY(My3Darray[1][1]) // Len = 4

Example 2

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
INTEGER Len INTEGER My3DArray[5][3][4] =
{
    {
        {1,2,3,4},
        {5,6,7,8},
        {9,10,11}
    },
    {
        {13,14}
    }
}

Len = LENGTH_ARRAY(My3Darray) (* Len = 2, the number of tables *)
Len = LENGTH_ARRAY(My3Darray[2]) (* Len = 1, the number of rows in table 2 *)
Len = LENGTH_ARRAY(My3Darray[1][3]) (* Len = 3, the number of columns in table 1, row 3 *)

See Also