IBM 5100 Basic Reference Manual page 50

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Arrays can be either one- or two-dimensional. A one-dimensional array can be
thought of as a row of successive data items. A two-dimensional array can be
thought of as a matrix of rows and columns. Figure 6 shows a schematic repre-
sentation of both types of arrays.
One-Dimensional Array Named A
A(1) A(2) A(3)
A(4)
Two-Dimensional Array Named 8
8(1,1) 8(1,2)
8(1,3)
8(2,1) 8(2,2) 8(2,3)
8(3,1)
8(3,2) 8(3,3)
8(4,1) 8(4,2) 8(4,3)
Figure 6. Schematic Representation of One- and Two-Dimensional Arrays
Each element in an array is referred to by the name of the array followed by a sub-
script in parentheses, which indicates the position of the element within the array.
The general form for referring to an array element is:
array name (rows, columns)
where array name is the name of the entire array, and rows, columns are any
positive arithmetic expressions whose truncated integer values are greater than zero
and less than or equal to the corresponding dimension of the array.
The expression in a subscript referring to an element of a one-dimensional array gives
the position of the element in the row, counting from left to right. Thus, the third
element of a one-dimensional array named A can
be
referred to by the symbol A(3),
as in this example:
A(3)
=
25
./
/