HP 3000 Manuals HP 3000 Manuals
REPEAT
The REPEAT and UNTIL statements define a loop that repeats until the
boolean expression in the UNTIL statement is TRUE (nonzero).
Syntax
REPEAT [stmt] . . . UNTIL boolean_expr
Parameters
stmt Program line that is executed until boolean_expr
evaluates to TRUE. These statements constitute the loop
body. The loop body is always executed once prior to
the evaluation of boolean_expr.
boolean_expr Considered FALSE if it evaluates to zero; TRUE
otherwise.
Examples
10 Nums_read=0
20 REPEAT !Begin loop
30 READ Number
40 Nums_read=Nums_read+1
50 UNTIL Number !End loop when Number<>0
60 PRINT Nums_read," numbers read"
99 END
REPEAT constructs can be nested.
100 REPEAT !Begin outer loop
110 READ Number1
120 REPEAT !Begin inner loop
130 READ Number2
140 UNTIL Number1-Number2 !End inner loop
150 UNTIL Number1+Number2 !End outer loop
160 PRINT Number1,Number2
999 END
Entering a REPEAT loop in the middle of the loop is considered to be a
bad programming practice, and is not recommended. However, calling a
local subroutine using GOSUB or calling an external subroutine using CALL
from within a REPEAT construct can be useful.
100 REPEAT !Begin loop
110 READ N1,N2
120 IF (N1 MOD 2) THEN GOSUB 200 !If N1 is odd, exit the loop
125 PRINT N1
130 UNTIL N2 !End loop
140 STOP
200 N1=2*N1
210 RETURN !Return to inside of loop
999 END