Are there any other kinds of loops besides counting loops?

Answer:

Yes. Many loops don't have a counter. For example, a loop might keep on going until some complicated goal has been achieved.

A Loop that is Not Counting

Loops that are not counting loops must use the DO WHILE statement (or an equivalent.) For example, here is a program that asks the user for a number, then types out its square root. The user can do this for as many numbers as desired. Since it is not known in advance how many numbers this will be, a DO WHILE loop must be used.

' Print out the square root of each number entered.
' A negative number is entered to exit the program.
'
PRINT "Enter a positive number"     
INPUT NUM
'
DO  WHILE NUM >= 0
  PRINT "The square root of", NUM, "is", SQR( NUM )
  PRINT "Enter a positive number"     
  INPUT NUM
LOOP 
'
END

This is not a counting loop, so the FOR statement is not appropriate.

QUESTION 2:

Are there times when you count, but count using a different pattern than "1, 2, 3, 4, ...."?