Author: Edward Shore (original article)
This is the first issue of a series of tutorials for the HP Prime, written by Edward Shore. If you have programmed with the HP 39g, 39g or 39gII, you will recognize the programming as the HP Prime programming language (HPPP) is similar. We are using the latest firmware in this series, available on the website.
A HPPP program is encased of an EXPORT - BEGIN - END structure. The layout is generally like this:
commands and comments go hereEND;
Each line containing a command generally must end with a semicolon (;).
A semicolon can by type by pressing
Comments can be typed. They are designated by two forward slashes.
The slashes are typed by pressing the
Anything in the line following the two slashes is ignored in running the program.
TIP: You can check the syntax of the program just by pressing the Check soft key in the program editor. HP Prime will Inform you if there is a syntax error and attempt to point you to the error. If there are no syntax errors, the Prime states "No errors in the program". I use the Check Command all the time.
Our first program is SQIN, because "Hello World" programs are so 2000s.
SQIN takes a number,
squares it, then calculates the reciprocal. In short we are defining a custom function:
RETURN returns a result to the stack (home page). You can return numbers, lists, vectors, matrices, strings, or a combination of these times.
EXPORT SQIN (X)
Home Mode - Textbook Entry, Home Mode - Algebraic Entry, CAS Mode:
Type the program name. Follow the name with parenthesis and enclose the required arguments.
Or use the
Home Mode - RPN Entry:
Enter each argument, separate each entry by pressing the
For example, if the program
TEST has four arguments, the RPN stack would like this:
4: argument_1 3: argument_2 2: argument_3 1: argument_4
TEST(4) to run the program.
Examples to try with SQIN:
LOCAL: Declares any variables to be local to the program. In other words, the variables are created, used, possibly displayed during program execution, and deleted at program termination.
MOPMT calculates the monthly payment of a loan.
The arguments are: the loan amount (L), the interest rate (R), and the number of months (M).
TIP: You can declare local variables and assign an initial value at the same time. For example:
LOCAL K:=1;stores 1 in K and makes K a local variable.
EXPORT MOPMT(L, R, M)
LOCAL K := R/1200; K := L*K / (1 - (1+K)^-M); RETURN "Payment = " + K;END;
TIP: Use RETURN, TEXTOUT_P, and PRINT to return custom strings, which combine results, messages, and calculations. Parts are connected with a plus sign.
MOPMT(4000, 9.5, 30) returns
MOPMT(370000, 3.5, 360) returns
Try this and next time in the series I will highlight other things we can do with HPPP.