# Variables; Typing Variable Names - HP 49g+ User Manual

Graphing calculator.

## Variables

Variables are similar to files on a computer hard drive. One variable can
store one object (numerical values, algebraic expressions, lists, vectors,
matrices, programs, etc). Variables are referred to by their names, which can
be any combination of alphabetic and numerical characters, starting with a
letter (either English or Greek). Some non-alphabetic characters, such as the
arrow ( ) can be used in a variable name, if combined with an alphabetical
character. Thus, ' A' is a valid variable name, but ' ' is not. Valid
examples of variable names are: 'A', 'B', 'a', 'b', ' ', ' ', 'A1', 'AB12',
' A12','Vel','Z0','z1', etc.
A variable can not have the same name as a function of the calculator. The
reserved calculator variable names are the following: ALRMDAT, CST, EQ,
EXPR, IERR, IOPAR, MAXR, MINR, PICT, PPAR, PRTPAR, VPAR, ZPAR, der_, e,
i, n1,n2, ..., s1, s2, ..., DAT, PAR, ,
Variables can be organized into sub-directories (see Chapter 2 in the
calculator's User's Guide).

### Typing variable names

To name variables, you will have to type strings of letters at once, which may
or may not be combined with numbers. To type strings of characters you can
lock the alphabetic keyboard as follows:
locks the alphabetic keyboard in upper case. When locked in this
~ ~
fashion, pressing the
before a letter key produces a lower case letter,
while pressing the
key before a letter key produces a special character.
If the alphabetic keyboard is already locked in upper case, to lock it in lower
case, type,
„ ~
locks the alphabetic keyboard in lower case. When locked
~ ~ „ ~
in this fashion, pressing the
before a letter key produces an upper case
letter. To unlock lower case, press
„ ~
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