A statement initialising a FOR…NEXT loop. The loop is executed at least once.
FOR temperature%=0 TO 9 FOR A(2,3,1)=9 TO 1 STEP -0.3
The FOR…NEXT loop is a way of repeating a section of program a set number of times. For example, the two programs below perform identically, but the second is easier to understand.
10 start=4: end=20: step=2 20 counter=start 30 PRINT counter," ",counter^2 40 counter=counter+step 50 IF counter<=end THEN 30 60 ...
10 start=4: end=20: step=2 20 FOR counter=start TO end STEP step 30 PRINT counter," ",counter^2 40 NEXT 50 ...
You can GOTO anywhere within one FOR…NEXT loop, but not outside it. This means you can't exit the loop with a GOTO. You can force a premature end to the loop with EXIT FOR or by setting the control variable to a value equal to or greater than the end value (assuming a positive STEP).
110 FOR I=1 TO 20 120 X=A^I 130 IF X>1000 THEN I=20: GOTO 150 140 PRINT I,X 150 NEXT
It is not necessary to declare the loop variable as an integer type in order to take advantage of fast integer arithmetic. If it is an integer, then fast integer arithmetic is used automatically.
Because a single stack is used, you cannot use a FOR…NEXT loop to set array elements to LOCAL in a procedure or function.
FOR <n-var>=<numeric> TO <numeric> [STEP <numeric>]