HP 48GII User Manual

RPL Programming 1-33
Error Trapping Commands
Key Programmable
Command
Description
!° L L %ERROR% :
%DOERR%
DOERR Causes an error. For a string in level 1, causes a user-defined error: the
calculator behaves just as if an ordinary error has occurred. For a binary
integer or real number in level 1, causes the corresponding built-in error.
If the error isn't trapped in an IFERR structure, DOERR displays the
message and abandons program execution. (For 0 in level 1, abandons
execution without updating the error number or message — like −.)
%ERRN%
ERNN Returns the error number, as a binary integer, of the most recent error.
Returns #0 if the error number was cleared by ERR0.
%ERRM%
ERRM Returns the error message (a string) for the most recent error. Returns
an empty string if the error number was cleared by ERR0.
%ERR0%
ERR0 Clears the last error number and message.
Making an Error Trap
You can construct an error trap with one of the following conditional structures:
! IFERR … THEN … END.
! IFERR … THEN … ELSE … END.
The IFERR … THEN … END Structure
The syntax for this structure is
!"!…!67<KK!trap-clause!:;<=!error-clause!<=4!…!1!
The commands in the error-clause are executed only if an error is generated during execution of the trap-clause.
If an error occurs in the trap-clause, the error is ignored, the remainder of the trap-clause is skipped, and
program execution jumps to the error-clause. If no errors occur in the trap-clause, the error-clause is skipped and
execution resumes after the END command.
To enter IFERR … THEN … END in a program:
! Press !°LL %ERROR% !%IFERR%.
Example: The following program takes any number of vectors or arrays from the stack and adds them to the
statistics matrix. However, the program stops with an error if a vector or array with a different number of
columns is encountered. In addition, if only vectors or arrays with the same number of columns are on the stack,
the program stops with an error after the last vector or array has been removed from the stack.
! "!Y;6E<!452!:P2<!V![[!K<2<B:!\'!<=4!1!
In the following revised version, the program simply attempts to add the level 1 object to the statistics matrix
until an error occurs. Then, it ends by displaying the message 4L=<.

HP 48GII Specifications

General

Battery type	CR2032
Type	Scientific
Form factor	Pocket

Weight and Dimensions

Weight	220 g
Dimensions (WxDxH)	184 x 87 x 23.5 mm

Summary

RPL Programming

Understanding Programs

Programs as objects, delimiters, and basic structure.

Entering and Executing Programs

Details on how to create, store, and run programs.

Using Conditional Structures

Covers IF, CASE, IFT, IFTE structures for program decision-making.

Input and Output Commands

Details commands like PROMPT, INPUT, INFORM, CHOOSE for user interaction.

RPL Programming Examples

Fibonacci Numbers

Demonstrates recursive and loop-based Fibonacci calculations.

Minimum and Maximum Array Elements

Details finding min/max elements using MNX and MNX2.

Applying a Program to an Array

Explains the APLY command for transforming array elements.

Full Command and Function Reference

How to Access Commands and Functions

Explains key presses and menu paths to access commands.

ABS (Absolute Value)

Details the absolute value function and its array behavior.

ACOS (Arc Cosine)

Explains the inverse cosine function, domain, and range.

Computer Algebra Commands

CAS Operations

Overview of CAS operations and their categorization by menu.

Algebra commands

Lists and describes commands for algebraic manipulation.

Calculus Commands

Covers derivation, integration, and limit commands.

Equation Reference

Columns and Beams (1)

Provides equations for structural mechanics.

Electricity (2)

Lists equations related to electrical circuits and laws.

Fluids (3)

Covers equations for fluid mechanics.

The Development Library

Introduction

Explains the purpose and usage of the development library.

Tools for Development

Details APEEK, PEEK, POKE, POKEARM commands.

MASD Compiler

Discusses syntax, modes, and directives for MASD.

Error and Status Messages

Messages Listed Alphabetically

Alphabetical list of error messages.

Messages Listed Numerically

Numerical list of error messages by hex code.

System Flags

System Flags (continued)

Description of various system flags.

System Flags (continued)

Continuation of system flags description.

Reserved Variables

Contents of the Reserved Variables

Explanation of key reserved variables.

PPAR

Details plotting parameters.

Technical Reference

Object Sizes

Lists object sizes in bytes.

Symbolic Integration Patterns

Provides a table of symbolic integration patterns.

Parallel Processing With Lists

General rules for parallel processing

Explains conditions for parallel list processing.

Group 4: ADD and +

Describes how ADD and + handle parallel list operations.

Keyboard Shortcuts

Press and Hold key combinations

Lists functions performed by key combinations.

Shifted softkeys

Explains shift key effects on menu labels.

The Menu-Number Table

-- menus 0-117 are semi-compatible with 48G menus --

Menu numbers and paths for built-in menus.

-- New Library 222 commands --

Details commands available in Library 222.