``` 70 c+=1 80 REPEAT UNTIL c>n 90 PRINT "I'll count a bit higher" 100 n+=1 110 REPEAT UNTIL n=10 120 PRINT "OK, I'm done now" ``` will work fine – try it and see if you can see what is happening. You can also make a **REPEAT** loop continue indefinitely, if you use a zero in the **REPEAT UNTIL** statement. Type in this program: ``` 10 REPEAT 20 PRINT "Hello world!" 30 REPEAT UNTIL 0 ``` It will continue printing **Hello world!** to the screen, stopping only to ask if you want to scroll (unless you press the **BREAK** key, of course). Why? Zero can be seen in *NextBASIC* as *false* when used in this way, so the **REPEAT UNTIL 0** statement will always give a *false* result; hence the loop will continue indefinitely. Obviously you can exit such a loop with **EXIT** if need be ### WHILE The **WHILE** command, used within a **REPEAT** loop, can provide an alternative way of leaving the loop before reaching the **REPEAT UNTIL** statement. If the condition in the **WHILE** statement is *true*, the loop continues. But if it is *false*, then the remaining statements in the loop will be ignored, the loop will be exited and the program will resume with the line after the **REPEAT UNTIL** statement. Try this: ``` 10 REPEAT 20 INPUT "Enter a number, or enter a negative number to stop > ";n 30 WHILE n>=0 40 PRINT n 50 REPEAT UNTIL 0 60 PRINT "Thank you!" ``` It is a different approach to the example seen earlier, this time using **WHILE** to check the number entered (and also accepting any negative number to stop). **WHILE** can also be used to exit a loop before any statements are executed, should you need to. Try: ``` 10 y=0 20 REPEAT : WHILE y<22 30 PRINT AT y,0;"This is line ";y;"." 40 y+=1 50 REPEAT UNTIL 0 ``` You will note that when **y** reaches 22, the loop will exit before printing the line number. It should also be pointed out that not only can you place a **WHILE** anywhere within the loop, but you can also place more than one **WHILE** in the same loop, if you have different conditions to check to leave the loop.