| type | description |
|---|---|
| counting loop | Uses a loop control variable to count upwards or downwards (usually by an integer increment.) |
| sentinel-controlled loop | Loop keeps going until a special value is encountered in the data. |
| result-controlled loop | Loop keeps going until a test determines that the desired result has been achieved. |
Each type of loop can be built using the
while
along with other statements.
There
are three things
(in every type of loop)
that must be done correctly:
Overlooking one of these aspects results in a defective loop. But usually each of these aspects is found in a different place in a program. No wonder that loops often go wrong!
The flow chart to the right shows what all loops must do. It could be for any of the three types of loops. The ellipses (. . . .) shows where the loop body does additional computation.
Would it be convenient to have all three aspects combined into one statement?