Introduction to BASIC   DO~LOOP

The statements written between a DO line and a LOOP line shall be executed repeatedly.
If an EXIT-DO statement is executed, the repetition finishes and the control branches to the line following the LOOP line.
Example. A program which displays "2+4=?" and ask an input until 6 is entered.

10 DO
20   PRINT "2+4=?"
30   INPUT n
40   IF n=2+4 THEN EXIT DO
60 END

Refer to DO~LOOP

IF line
Line 40 of the above program is a IF Line.
On a IF line, one statement can be written on the rihgt hand side of THEN.
A IF line has no corresponding END-IF line .

Refer to IF statement