Sequence and selection are control structures we have already used. Looping also called Iteration is another powerful control structure. Looping allows us to execute the same instruction(s) (typically with different data sets) over and over using the same code.
Pseudo code to print all the numbers between 1 and 10
Counter = 1
Do as long as Counter is <= 10
Print counter
Counter = Counter + 1
End loop
Pseudo code to print the sum of numbers between 1 and 1,
and then the sum of numbers between 1 and 2, and then 1 and 3, and so on.
Counter = 1
Total = 0
Do until Counter > 10
Total = Total + Counter
Output “Sum of numbers between 1 and “ & Counter & “ = “ &
Total
Counter = Counter + 1
End Loop
Output Total
Note: Something must happen inside the
loop so that the result of the condition changes. If the condition DOES NOT
change you will be in an infinite loop.