cplusplus:control_structures_repetition_in_algorithms

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Control Structures: Repetition in algorithms

Mithat Konar
2013-02-03

Introduction

Input validation
Sentinel/flag control
- Menus
Counter control
Iterators

Input validation

Do not continue with program until user has entered valid data.

Pseudo code:

Get input value from user
While input value is not valid
    Get input value from user

Sentinel/flag control

Sentinel:
- Value(s) that indicate(s) a special condition; “special value”
Flag:
- Sometimes used as a synonym for sentinel
- Sometimes means a sentinel that is a Boolean value

Sentinel-controlled repetition

Sentinel-controlled repetition:
- Repeat as long as a sentinel condition is not matched
- Pseudo code:
```
While input value is not -999
    do something
```
Input validation might be considered a special case of sentinel controlled repetition.

Menus

Repeating menus can be implemented with sentinel control.

Pseudo code:

Show menu
Get menu choice from user
While input value is not QUIT value
    <Process the menu choice>
    Show menu
    Get menu choice from user

Counter control

TODO

Iterators

TODO

cplusplus/control_structures_repetition_in_algorithms.1361319407.txt.gz · Last modified: 2013/02/20 00:16 by mithat