User's Manual

550 Programming in HP PPL
Returns true (not zero) if the user selects an object,
otherwise return false (0).
Example:
CHOOSE
(N,"PickHero",
"Euler","Gauss
","Newton");
IF N==1 THEN
PRINT("You
picked
Euler"); ELSE
IF N==2 THEN PRINT("You picked
Gauss");ELSE PRINT("You picked
Newton");
END;
END;
After execution of CHOOSE, the value of N will be updated
to contain 0, 1, 2, or 3. The IF THEN ELSE command
causes the name of the selected person to be printed to
the terminal.
EDITLIST Syntax: EDITLIST(listvar)
Starts the List Editor loading listvar and displays the
specified list. If used in programming, returns to the
program when user taps .
Example: EDITLIST(L1) edits list L1.
EDITMAT Syntax: EDITMAT(matrixvar)
Starts the Matrix Editor and displays the specified matrix.
If used in programming, returns to the program when user
taps .
Example: EDITMAT(M1) edits matrix M1.
GETKEY Syntax: GETKEY
Returns the ID of the first key in the keyboard buffer, or –1
if no key was pressed since the last call to GETKEY. Key
IDs are integers from 0 to 50, numbered from top left (key
0) to bottom right (key 50) as shown in figure 27-1.