Application Guide

39 Variables Overview

Data type Examples

Expression 2.54 1.25E6 2p (x-2)

List {2, 4, 6, 8} {1, 1, 2} {"red", "blue", "green"}

Matrix This can be entered as: [1,2,3;3,6,9]

Character string "Hello" "xmin/10" "The answer is:"

Function, program myfunc(arg ) ellipse(x, y, r1, r2)

Measurement area perimeter length slope angle

Naming Variables and Functions

Names for variables and functions that you create must meet the following naming

rules.

Note: If you create a variable with the same name as one used for statistical analysis

or by the Finance functions, an error condition could occur. When you enter the name

of a variable that is already in use in the current problem, the entry is shown in bold.

• Variable names must be in one of the forms xxx or xxx.yyy. The xxx part can have

1 to 16 characters. The yyy part, if used, can have 1 to 15 characters. You cannot

start or end the variable name with a period (.).

• Characters can consist of letters, digits, and the underscore character (_). Letters

can be U.S. or Greek letters (but not Π or π), accented letters, and international

characters.

• Do not use c or n from the symbol palette to construct a variable name such as c1

or n12. These may appear to be letters, but they are treated internally as special

symbols.

• You can use uppercase or lowercase letters. The names AB22, Ab22, aB22, and

ab22 all refer to the same variable.

• You cannot use a digit as the first character of xxx or yyy.

• When entering a subscript, you can use digits zero through 9, U.S. letters, a

through z, Latin and Greek letters (but not π) as subscripts (for example, a

, q

, or

o). To enter a subscript while typing a variable name, touch and hold , and

then slide to select .

• Do not use spaces.

• If you want a variable to be treated as a complex number, use an underscore as the

last character of the name.