2.5
String Function
2.5.1
LEN
I Format
Function
Example
LEN (X$)
X$ . . . String expression
This funcion returns the number
of
characters included in
the
string expression
represented
by
X$. This value includes spaces which are
not
displayed
on
the screen
and any control characters in
the
string,
as
well
as
letters, numerals,
and
symbols.
(Example
1)
1 0
A$=
aAB
COE
FG "
2 0 P
RINT
LE
N C
A$
)
RUN
7
(Example 2) The following program uses
the
LEN funcition to draw squares on the
screen.
1 0
9
"
~
"
:?
"
ENTER
30R
MORE
AS
T
ER
I
SKS
"
2 0
INP
UT
A$
3 0 FOR 1= 1 TO LEN C
A$)-2
4 0 P R I NT TA B
C2)
; " * " ; S PC CLEN C
A$)
-2)
" * "
5 0 NEX T I
6 0
PRINT
TAB
C2)
;
A$
: GOTO 2 0
(Example 3)
The
LEN function can also be used to produce a
"parade"
of
charac-
ters
as
shown below.
1 0
S$
= "S H
ARP
BASIC
"
20
FOR
1
=1
TO
LEN
C
S$)
30
9 R IGHT
$CS$.
I)
4 0 NE XT
5 0 END
RUN
c
IC
SIC
S HA
RP
BAS
IC
(Example 4)
PRINT
LEN
CS
TR$
CPA I C1 ))) J
g
PAl
(1)
, the function which returns the value
of
the ratio
of
the circumference
of
a
circle
to
its diameter, contains the 8-digit constant
3.1415927
(approximately the
value
of
PI). When the length
of
the character string produced
by
converting this
constant with the STR$ function
is
evaluated with the LEN function, a
total
string
length
of
9
is
returned.
76
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