EasyManuals Logo

HP HP-28S User Manual

HP HP-28S
341 pages
To Next Page IconTo Next Page
To Next Page IconTo Next Page
To Previous Page IconTo Previous Page
To Previous Page IconTo Previous Page
Page #201 background imageLoading...
Page #201 background image
Evaluation of Local
Names
As described
in
chapter
19,
the
use
of
local variables simplifies stack
manipulations. The
purpose
of
local variables is (1) to remove
the
variable's contents from
the
stack so it's
out
of
the
way
and
(2) to
return
a copy
of
the
variable's contents
whenever
you
need
it. Conse-
quently, evaluating a local
name
always
returns
the
contents
of
the
corresponding local variable to
the
stack.
Evaluation of Global
Names
In general, evaluating a global
name
causes evaluation
of
the
contents
of
the
corresponding global variable. In
other
words, evaluating a
global
name
has
the
same
effect as evaluating
the
object
it
represents.
There are two exceptions to
the
general rule:
•
If
no
variable exists
with
the
specified
name,
the
name
is
returned
to
the
stack.
An
undefined
name
used
as a variable is called a
for-
mal
variable.
•
If
the
contents
of
the
specified variable is
an
algebraic,
the
algebraic
is
not
evaluated.
The
calculator avoids evaluation
of
these objects so
you can
continue
symbolic calculations.
If
you
do
want
evaluation,
execute
the
command
EVAL
with
the
algebraic
in
level 1.
(To
eval-
uate
an
algebraic repeatedly
until
it produces a numerical result,
execute
....
NUM.)
If
the
variable contains a data-class object, evaluating
the
variable's
name
is equivalent to simply recalling
the
variable's contents.
How-
ever, evaluating a variable's
name
can
lead
to a long
chain
of
evaluations. For example, if a variable contains a
name,
and
that
name
is
the
name
of
a second variable,
and
the
second
variable con-
tains a name,
and
that
name
is
the
name
of
a third variable,
then
evaluating
the
name
of
the
first variable ultimately causes evaluation
of
contents
of
the
third
variable.
200
23:
Evaluation
I

Table of Contents

Other manuals for HP HP-28S

Questions and Answers:

Question and Answer IconNeed help?

Do you have a question about the HP HP-28S and is the answer not in the manual?

HP HP-28S Specifications

General IconGeneral
BrandHP
ModelHP-28S
CategoryCalculator
LanguageEnglish

Related product manuals