Sharp PC-1500 Instruction Manual page 49

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Normally, of course, this program would
~xccutc
in ascending line-number sequence. The
effect of the GOTO in line 20. however, is to cause SHARP to proceed immediately to line 50
and to begin in ascending sequence from there, lines
30 and 40
arc never cxccu'ted.
The
general form of
the GOTO statement
is:
£QIQ
expression
\Yhere:
expression cv.aluates to a number which is a valid program line-number
(i.e.
1 through 65279) .
NOTE: Specifying a line·number which does not exist will result in an ERROR
11.
If we wish to have several instructions executed as a result of a certain choice
we
use GOTO
statements in conjunction with the IF:
10
!E.
test TH EN GOTO
100
20
l
statements here arc }
l
performed only if the }
\ test is False.
I
90 GOTO 200
100
l
statements here are
l
performed only if the
l
test is True.
200 { statements here arc
{ always performed.
999 ENO
The logic of this program is applicable to many situations. Any number
of
statements can be
inserted in each of the sections which are fo rmed by the GOTO statements.
As an example of this structure in practice, the following segment from a checkbook program
determines whether a given input amount is a deposit {positive number)or a withdrawal(negative
number). An initial balance is entered by the user:
Program Listing:
10 INPUT "INITIAL BALANCE?", B
20 INPUT " TRANSACTION AMOUNT?", TA
25 IF TA = 0 THEN GOTO 80
30 B = B + A
40 IF TA< 0 THEN GOTO 70
50 PR INT "DEPOSIT OF $";TA; " POSTED"
60 GOTO 80
70 PRI NT TA; " DOLLARS WITHDRAWN"
80 PRINT "FINAL BALANCE = "; B
90 ENO
47
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