HP 3000 Manuals HP 3000 Manuals
ON GOSUB
The ON GOSUB statement is one of the GOSUB corollaries of the ON GOTO and
GOTO OF statements. Control is transferred to the selected line, L, by
"GOSUB L" rather than "GOTO L." A RETURN statement returns control to the
statement that follows the ON GOSUB statement. Although the ON GOSUB
statement can be input as ON GOSUB or ON GO SUB, HP Business BASIC/XL
will always list it as ON GOSUB.
Syntax
{GOSUB }
ON num_expr {GO SUB} line_id [, line_id]...[ELSE else_line_id]
Parameters
num_expr A numeric expression that is evaluated and converted to
an integer, n. The integer n must be between one and
the number of line_ids, or an error occurs if no ELSE
clause is present. Control is transferred to the nth
line_id.
line_id Line number or line label of the line to which control
is transferred. The line must be in the same program
unit as the ON GOSUB statement.
else_line_id Line number or line label of the line to which control
is transferred if the value of num_expr is not between
one and the number of line_ids specified.
Examples
1 READ I, J
2 ON I GOSUB 10,20,30 !Go to subroutine at line 10, 20, or 30
3 ON J GOSUB 40,50,60 ELSE 99 !Go to subroutine at line 40,50, or 60 or to
!line 99
4 STOP !if J < 1 or J > 3
10 REM Subroutine for I=1
11 PRINT "I is one"
12 RETURN !Return to line 3
20 REM Subroutine for I=2
21 PRINT "I is two"
22 RETURN !Return to line 3
30 REM Subroutine for I=3
31 PRINT "I is three"
32 RETURN !Return to line 3
40 REM Subroutine for J=1
41 PRINT "J is one"
42 RETURN !Return to line 4
50 REM Subroutine for J=2
51 PRINT "J is two"
52 RETURN !Return to line 4
60 REM Subroutine for J=3
61 PRINT "J is three"
62 RETURN !Return to line 4
90 DATA 3,2
99 END
The GOSUB OF statement works exactly the same as the ON GOSUB statement.
The following statements are equivalent:
150 ON I GOSUB 10, 20, 30, Quit
150 GOSUB I OF 10, 20, 30, Quit