Introduction
This article explains Control Structure Testing and Loop Testing. Control Structure Testing is a part of white box testing, it includes the following methods:
- Condition Testing
- Loop Testing
- Data validation testing
- Path testing
Here I am explaining Loop Testing.
Loop Testing
Loops are fundamental for the vast majority of all algorithms implemented in software. Loop Testing is a white box testing technique that entirely concentrates on the validity of loop constructs.
Types of Loops
Loops are of the following four types:
- Simple Loop
- Nested Loops
- Concatenated Loops
- Unstructured Loops
Simple Loops
![Simple Loops.jpg]()
A simple loop is tested in the following way:
- Skip the entire loop.
- Make 1 pass through the loop.
- Make 2 passes through the loop.
- Make x passes through the loop where x<y, n is the maximum number of passes through the loop.
- Make "y","y-1","y+1" passes throug the loop where "y" is the maximum number of allowable passes through the loop.
Nested Loop
![Nested Loop.jpg]()
A nested loop is tested in the following way:
- A nested loop starts at the innermost loop.
- For the innermost loop, conduct a simple loop test.
- Work outward.
- Continue until the outermost loop has been tested.
Concatenated Loops
![Concatenated Loop.jpg]()
To test concatenated loops the procedure is:
If the loops are independent then test them as simple loops or else test them as nested loops.
Unstructured Loops
![Unstructured Loops.jpg]()
These are unstructured loops. To test them one needs to restructure the design to reflect the use of the structured programming constructs.