TOPS-20 PASCAL Language Manual - Bitsavers

P~SCAL
DATA TYPES
When referring to the components of Two D, the first component in the
first row is Two Dro,'.a.'l. The second component in this row is
Two D ro,' B' 1. The Ii rst component in the second row is Two D rl,' A'] •
The- last component in the last row is Two Dr4,'D']. In general,
element j of row i is Two_Dri,jl. -
You can define arrays of three or more dimensions in a similar
fashion, for example:
V A F< C h (.;.~ s s :3 II : . f.l f< F< A Y [1..;3 ~ :I... n, n r::. • 1\ F< ::I 0 F C h (.:.~ ~:; ~:; 1'1'1 e 1"1 ;
This declaration specifies a three-dimensional chess game. The
indices of the array are the levels, the ranks, and the files of the
chessboard. For example, the reference Chess3D fI, 1, QR] specifies
the first level, first square in the upper left corner (bottom lev~l,
first rank, Queen's Rook file). Figure 2-2 illustrates the three
levels of this array.
Chess3D(1,n,
Chessmen)
(bottom)
Chess3D(2,n,
Chessmen)
(middle)
Chess3D(3,n,
Chessmen)
( top)
1 OR ON OS 0 K KS KN KR
Cf-IESS3D{3.n. CHESSMEN/
CHESS3D{2.n.CHESSMEN/
CHESS3D{I.n.CHESSMENj
lK 098 81
Figure 2-2:
Three-Dimensional Array Chess3D
When storing values in an array, PASCAL increments the indices from
right to left. Thus, PASCAL increments the rightmost index until the
maximum value is reached, then moves to the left to the next index,
and so on, until all indices have been incremented to the specified
amoun t.
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