Texas Instruments TI-89 Voyage 200, Руководство пользователя

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Appendix A: Functions and Instructions 833
isLocked()
CATALOG
isLocked( var_name )
⇒ ⇒ ⇒ ⇒
true,false
Determines if
var_name
is locked or not.
Returns
true
if
var_name
is locked or archived.
Returns
false
if
var_name
is not locked or
archived.
isLocked(PROG1)
¸
False
isPrime()
MATH/Test menu
isPrime(
number
)
⇒
⇒ ⇒
⇒
Boolean constant expression
Returns true or false to indicate if
number
is a
whole number
‚
2 that is evenly divisible only by
itself and 1.
If
number
exceeds about 306 digits and has no
factors

1021,
isPrime(
number
)
displays an
error message.
If you merely want to determine if number is
prime, use
isPrime()
instead of
factor()
. It is
much faster, particularly if number is not prime
and has a second-largest factor that exceeds
about five digits.
IsPrime(5)
¸
true
IsPrime(6)
¸
false
Function to find the next prime after a specified
number:
Define nextPrim(n)=Func:Loop:
n+1
!
n:if isPrime(n):return n:
EndLoop:EndFunc
¸
Done
nextPrim(7)
¸
11
isVar()
CATALOG
isVar( var_name )
⇒
⇒ ⇒
⇒
true,false
Determines if var_name is in use. Returns
true
if var_name exists. Returns
false
if var_name
does not exist.
isArchiv(PROG1)
¸
True
Item
CATALOG
Item
itemNameString
Item
itemNameString
,
label
Valid only within a
Custom...EndCustm
or
ToolBar...EndTBar
block. Sets up a drop-down
menu element to let you paste text to the cursor
position (
Custom
) or branch to a label
(
ToolBar
).
Note: Branching to a label is not allowed within
a
Custom
block.
See Custom example.
Lbl
CATALOG
Lbl
labelName
Defines a label with the name
labelName
in the
program.
You can use a
Goto
labelName
instruction to
transfer program control to the instruction
immediately following the label.
labelName
must meet the same naming
requirements as a variable name.
Program segment:
©
:Lbl lbl1
:InputStr "Enter password", str1
:If str1
ƒ
password
: Goto lbl1
:Disp "Welcome to ..."
©