Array Types  57  Arrays provide a means of grouping under a single name several  variables  having  identical  characteristics.  An  array  variable  declaration gives a name to the entire array structure. Two operations  valid  for  entire  array  variables  are  assignment  and  selection  of  components. A component is selected by specifying the name of the  array variable followed by an ordinal expression enclosed in square  brackets. The operations permitted on such a component variable are  those which are valid for any variable of the component type of that  array type.  Examples of variable declarations:  Examples of sample assignments:  (Of course these examples assume the definition of the auxiliary  identifiers. )  Programs 6.1 and 6.2 illustrate the use of arrays. Consider how you  would extend Program 6.2 to plot more than one function - both with  and without the use of an array.  Figure 6.c  Syntax Diagram for  ComponentVariable  ~r--~  Variable  I----or--~  I----o::;r---i~  OrdinalExpression  I--~~  )----..,-1 Fieldldentifier  1--------/  Memory [I+J)  := X  Sick[Mon)  := true  Memory:  array  [0 .. Max)  of Integer  Sick:  packed array  [Days)  of Boolean 