Sharp MZ-700 - Page 49

2.3.6 Loop and branch instructions
2. 3. 6. 1 FOR~ NEXT . . ........... .. ........... . .. ...... (abbreviated format: F.~ N.)
I Format I FOR cv = iv TO fv < STEP sv >
Function
NEXT<cv>
cv . . . . Control variable; a numeric variable or array element .
iv Initial value; a
numeric expression.
fv .... Final value; a numeric expression.
sv . . .. Increment, or step value; a numeric expression (if omitted, 1 is assumed).
This
statement repeats the instructions between FOR and NEXT a certain number
of times.
10
A= 0
20
FOR
N=0 TO
1 0
STEP 2
30
A=A+1
4 0 PRINT
11 N== 11
; N.
50 PRINT
11 A== 11
;A
60
NE XT N
( 1) In the program above, 0 is assigned to N as the initial value.
(2)
Next, lines 20 through 50 are executed and the values of variables A and N
displayed.
(3)
In line 60, the value of N is increased by 2, after which the BASIC interpreter
checks to see whether N is greater than 10, the final value. If not, lines following
line
20 are repeated.
When the value of N exceeds 10, execution leaves the loop and subsequent instruc-
tions (on lines following line 60) are executed. The program above repeats the loop
6 times.
If< STEP sv > is omitted from the statement specification, the value of N is increas-
ed by 1 each time the loop is repeated. In the case of the program above, omitting
< STEP sv > in this manner would result in 11 repetitions of the loop .
FOR
c- -- - -------~
l N =O [
I I
L -- ------ -l
Loop control
variable
.- ----- - -- ---- - ----- ----- -----r
I I
[ TO 1 0 STEP 2 :
t_ ___ _ ____ _ -------- -- ---. I
Final value
of N
I
I
I
I
I
I
I
Increment
for N (step)
Initial value
of N
I
I I
;-- ------------ ---- ------·--- ------------------ ---' :
: NEXT N :
L _______ -- --- -- ------------ --- ---- ---- - ------ ____ j
-------------------------------------------------------- ----------------47