Returns a component of a variable name.
The format of the $QSUBSCRIPT function is:
$QS[UBSCRIPT](namevalue, intexpr)
The namevalue has the form of an evaluated subscripted or unsubscripted global or local variable name.
The intexpr selects the component of the name as follows:
-2 : is reserved but may be "error",
-1 : for environment,
0 : for the unsubscripted name,
1 : for the first subscript,
2 : for the second subscript, and so on.
If the second argument selects a component that is not part of the specified name, $QSUBSCRIPT() returns an empty string ("").
Example:
Assume that X is defined as in the "Examples of $Qlength()" earlier in this chapter;
write X X="^|""XXX""|ABC(1,2,3,5,6)" GTM>write $qsubscript(X,-2) error GTM>WRITE $qsubscript(X,-1) XXX GTM>WRITE $qsubscript(X,0) ^ABC GTM>WRITE $qsubscript(X,1) 1 GTM>WRITE $qsubscript(X,4) 5 GTM>WRITE $qsubscript(X,7) ""
